diff --git a/form.php b/form.php
index dd9ed59..1c33634 100644
--- a/form.php
+++ b/form.php
@@ -34,23 +34,25 @@ class form
     $this->formName = $formName;
   }
 
-  /** Save the fields into the structure.
+  /** Save the array of fields into the structure.
       Available :
-      - name       : name of the field in the HTML page
-      - label      : label written to the describe the field
-      - [titles]   : text written in radio/checkboxes
-      - [defaults] : default values. Must be array for checkbox/select, and
-                     string for others
-      - [type]     : text, password, hidden, checkbox, select, radio, submit,
-                     textarea
-                     text by default
-      - [multiple] : Multiple selection are possible (if the type supports it)
-      - [group]    : define a fieldset and define the title with groupe name
-                     Warning : all the elements of the same group must be
-                     consecutive !
-      - [readonly] : put a read-only flag on the field (the user see it but
-                     can't interract on it. The value will be sent to next
-                     page
+      - name        : name of the field in the HTML page
+      - label       : label written to the describe the field
+      - [titles]    : text written in radio/checkboxes
+      - [defaults]  : default values. Must be array for checkbox/select, and
+                      string for others
+      - [type]      : text, password, hidden, checkbox, select, radio, submit,
+                      textarea
+                      text by default
+      - [help]      : The Help message (written below the field). Overwrite in
+                      case of error
+      - [multiple]  : Multiple selection are possible (if the type supports it)
+      - [group]     : define a fieldset and define the title with groupe name
+                      Warning : all the elements of the same group must be
+                      consecutive !
+      - [readonly]  : put a read-only flag on the field (the user see it but
+                      can't interract on it. The value will be sent to next
+                      page
       - [mandatory] : boolean to add a red star at end of label
       - [hidden]    : hide the field (add a style='display:hidden' to the field)
       - [rows]      : Number of rows
@@ -63,6 +65,13 @@ class form
     $this->fields = $fields;
   }
 
+  /** Add a field to the form. For the details of a field, see the description 
+      in fields method */
+  public function addfield ($field)
+  {
+    $this->fields[] = $field;
+  }
+
   /** Return the values provided by the user. Test the CSRF before continue
       NEVER read the values from $_POST in your codes or CSRF will not be
       checked */
@@ -129,6 +138,8 @@ class form
   public function printHTML ($method = 'post', $values = NULL,
                              $errors = array())
   {
+    if (count ($this->fields) === 0)
+      throw new Exception ("Can't display a form without defined field", 500);
     $this->method = strtolower ($method);
     $res = "";
     $res = "<form action='#' method='$method'";
@@ -204,6 +215,9 @@ class formfield
   public $defaults;
   /** The type of the field (text, password, checkbox, select)*/
   public $type="text";
+  /** Allow a help message to be displayed below the field. In case of error,
+      it is override by the error message */
+  public $help;
   /** The multiplicity of selection of the field (available in select only)*/
   public $multiple;
   /** The name of group for the fields */
@@ -251,15 +265,16 @@ class formfield
     $res .= ">";
     $res .= htmlspecialchars ($this->label);
     if (isset ($this->mandatory) && $this->mandatory !== FALSE)
-      $res .= "&nbsp;<span style='color:red'>*</span>";
+      $res .= " <span style='color:red'>*</span>";
     else
-      $res .= "&nbsp;&nbsp;";
+      $res .= "  ";
     $res .= "</label>\n";
     $res .= "    <div class='col-sm-10'>\n";
     if (is_string ($this->defaults))
       $this->defaults = array ($this->defaults);
     foreach ($this->titles as $key=>$val)
     {
+      $res .= "<div class='checkbox'>";
       $res .= "      <input type='hidden'";
       $res .= " name='$this->formName"."[";
       $res .= htmlspecialchars ($this->name, ENT_QUOTES)."][$key]'";
@@ -278,16 +293,30 @@ class formfield
       elseif (isset ($this->defaults[$key]) &&
               $this->defaults[$key] !== "")
         $res .= " checked='checked'";
-      $res .= " class='form-control'";
       if (isset ($this->hidden) && $this->hidden !== FALSE)
         $res .= " style='display:none'";
+      if (isset ($this->errors) || isset ($this->help))
+      {
+        $res .= " aria-describedby='".$this->formName."_";
+        $res .= htmlspecialchars ($this->name, ENT_QUOTES)."_help'";
+      }
       $res .= "/>";
       $res .= "$val\n";
+      $res .= "</div>\n";
     }
 
     if (isset ($this->errors))
-      $res .= "      <span class='help-block'>".$this->errors[1].
+    {
+      $res .= "      <span class='help-block' id='$this->formName"."_";
+      $res .= htmlspecialchars ($this->name, ENT_QUOTES)."_help'>".
+              $this->errors[1]."</span>\n";
+    }
+    elseif (isset ($this->help))
+    {
+      $res .= "      <span class='help-block' id='$this->formName"."_";
+      $res .= htmlspecialchars ($this->name, ENT_QUOTES)."_help'>".$this->help.
               "</span>\n";
+    }
     $res .= "    </div>\n"; // End controls
     $res .= "  </div>\n"; // End form-group
     return $res;
@@ -329,9 +358,9 @@ class formfield
     $res .= ">";
     $res .= htmlspecialchars ($this->label);
     if (isset ($this->mandatory) && $this->mandatory !== FALSE)
-      $res .= "&nbsp;<span style='color:red'>*</span>";
+      $res .= " <span style='color:red'>*</span>";
     else
-      $res .= "&nbsp;&nbsp;";
+      $res .= "  ";
     $res .= "</label>\n";
     $res .= "    <div class='col-sm-10'>\n";
     $res .= "      <input type='password'";
@@ -350,10 +379,26 @@ class formfield
     $res .= " class='form-control'";
     if (isset ($this->hidden) && $this->hidden !== FALSE)
       $res .= " style='display:none'";
+    if (isset ($this->cols))
+      $res .= " size='".$this->cols."'";
+    if (isset ($this->errors) || isset ($this->help))
+    {
+      $res .= " aria-describedby='".$this->formName."_";
+      $res .= htmlspecialchars ($this->name, ENT_QUOTES)."_help'";
+    }
     $res .= "/>\n";
     if (isset ($this->errors))
-      $res .= "      <span class='help-block'>".$this->errors[1].
+    {
+      $res .= "      <span class='help-block' id='$this->formName"."_";
+      $res .= htmlspecialchars ($this->name, ENT_QUOTES)."_help'>".
+              $this->errors[1]."</span>\n";
+    }
+    elseif (isset ($this->help))
+    {
+      $res .= "      <span class='help-block' id='$this->formName"."_";
+      $res .= htmlspecialchars ($this->name, ENT_QUOTES)."_help'>".$this->help.
               "</span>\n";
+    }
     $res .= "    </div>\n"; // End controls
     $res .= "  </div>\n"; // End form-group
     return $res;
@@ -376,9 +421,9 @@ class formfield
     $res .= ">";
     $res .= htmlspecialchars ($this->label);
     if (isset ($this->mandatory) && $this->mandatory !== FALSE)
-      $res .= "&nbsp;<span style='color:red'>*</span>";
+      $res .= " <span style='color:red'>*</span>";
     else
-      $res .= "&nbsp;&nbsp;";
+      $res .= "  ";
     $res .= "</label>\n";
     $res .= "    <div class='col-sm-10'>\n";
     if (is_string ($this->defaults))
@@ -390,7 +435,8 @@ class formfield
     $res .= "/>\n";
     foreach ($this->titles as $key=>$val)
     {
-      $res .= "      <label class='radio'>";
+      $res .= "<div class='radio'>";
+      $res .= "      <label>";
       $res .= "<input type='radio'";
       $res .= " name='$this->formName"."[";
       $res .= htmlspecialchars ($this->name, ENT_QUOTES)."]'";
@@ -405,17 +451,31 @@ class formfield
       elseif (isset ($this->defaults[0]) &&
               $this->defaults[0] === $val)
         $res .= " checked='checked'";
-      $res .= " class='form-control'";
       if (isset ($this->hidden) && $this->hidden !== FALSE)
         $res .= " style='display:none'";
+      if (isset ($this->errors) || isset ($this->help))
+      {
+        $res .= " aria-describedby='".$this->formName."_";
+        $res .= htmlspecialchars ($this->name, ENT_QUOTES)."_help'";
+      }
       $res .= "/>";
       $res .= "$val";
       $res .= "</label>\n"; // End label radio
+      $res .= "</div>";
     }
 
     if (isset ($this->errors))
-      $res .= "      <span class='help-block'>".$this->errors[1].
+    {
+      $res .= "      <span class='help-block' id='$this->formName"."_";
+      $res .= htmlspecialchars ($this->name, ENT_QUOTES)."_help'>".
+              $this->errors[1]."</span>\n";
+    }
+    elseif (isset ($this->help))
+    {
+      $res .= "      <span class='help-block' id='$this->formName"."_";
+      $res .= htmlspecialchars ($this->name, ENT_QUOTES)."_help'>".$this->help.
               "</span>\n";
+    }
     $res .= "    </div>\n"; // End controls
     $res .= "  </div>\n"; // End form-group
     return $res;
@@ -438,9 +498,9 @@ class formfield
     $res .= ">";
     $res .= htmlspecialchars ($this->label);
     if (isset ($this->mandatory) && $this->mandatory !== FALSE)
-      $res .= "&nbsp;<span style='color:red'>*</span>";
+      $res .= " <span style='color:red'>*</span>";
     else
-      $res .= "&nbsp;&nbsp;";
+      $res .= "  ";
     $res .= "</label>\n";
     $res .= "    <div class='col-sm-10'>\n";
     if (isset ($this->defaults) && is_array ($this->defaults))
@@ -484,6 +544,11 @@ class formfield
       $res .= " class='form-control'";
       if (isset ($this->rows))
         $res .= " size='".$this->rows."'";
+      if (isset ($this->errors) || isset ($this->help))
+      {
+        $res .= " aria-describedby='".$this->formName."_";
+        $res .= htmlspecialchars ($this->name, ENT_QUOTES)."_help'";
+      }
       $res .= ">\n";
       foreach ($this->defaults as $key=>$val)
       {
@@ -504,8 +569,17 @@ class formfield
 
       $res .= "      </select>\n";
       if (isset ($this->errors))
-        $res .= "      <span class='help-block'>".$this->errors[1].
-                "</span>\n";
+      {
+        $res .= "      <span class='help-block' id='$this->formName"."_";
+        $res .= htmlspecialchars ($this->name, ENT_QUOTES)."_help'>".
+                $this->errors[1]."</span>\n";
+      }
+      elseif (isset ($this->help))
+      {
+        $res .= "      <span class='help-block' id='$this->formName"."_";
+        $res .= htmlspecialchars ($this->name, ENT_QUOTES)."_help'>".$this->help
+                ."</span>\n";
+      }
     }
     else
     {
@@ -563,9 +637,9 @@ class formfield
     $res .= ">";
     $res .= htmlspecialchars ($this->label);
     if (isset ($this->mandatory) && $this->mandatory !== FALSE)
-      $res .= "&nbsp;<span style='color:red'>*</span>";
+      $res .= " <span style='color:red'>*</span>";
     else
-      $res .= "&nbsp;&nbsp;";
+      $res .= "  ";
     $res .= "</label>\n";
     $res .= "    <div class='col-sm-10'>\n";
     $res .= "      <textarea";
@@ -584,6 +658,11 @@ class formfield
     if (!isset ($this->rows))
       $this->rows = 4;
     $res .= " rows='".$this->rows."'";
+    if (isset ($this->errors) || isset ($this->help))
+    {
+      $res .= " aria-describedby='".$this->formName."_";
+      $res .= htmlspecialchars ($this->name, ENT_QUOTES)."_help'";
+    }
     $res .= ">";
     if (isset ($this->values))
       $res .= htmlspecialchars ($this->values, ENT_QUOTES);
@@ -591,8 +670,17 @@ class formfield
       $res .= htmlspecialchars ($this->defaults, ENT_QUOTES);
     $res .= "</textarea>\n";
     if (isset ($this->errors))
-      $res .= "      <span class='help-block'>".$this->errors[1].
-              "</span>\n";
+    {
+      $res .= "      <span class='help-block' id='$this->formName"."_";
+      $res .= htmlspecialchars ($this->name, ENT_QUOTES)."_help'>".
+              $this->errors[1]."</span>\n";
+    }
+    elseif (isset ($this->help))
+    {
+      $res .= "      <span class='help-block' id='$this->formName"."_";
+      $res .= htmlspecialchars ($this->name, ENT_QUOTES)."_help'>".$this->help
+              ."</span>\n";
+    }
     $res .= "    </div>\n"; // End controls
     $res .= "  </div>\n"; // End form-group
     return $res;
@@ -615,9 +703,9 @@ class formfield
     $res .= ">";
     $res .= htmlspecialchars ($this->label);
     if (isset ($this->mandatory) && $this->mandatory !== FALSE)
-      $res .= "&nbsp;<span style='color:red'>*</span>";
+      $res .= " <span style='color:red'>*</span>";
     else
-      $res .= "&nbsp;&nbsp;";
+      $res .= " ";
     $res .= "</label>\n";
     $res .= "    <div class='col-sm-10'>\n";
     $res .= "      <input type='text'";
@@ -636,10 +724,26 @@ class formfield
     $res .= " class='form-control'";
     if (isset ($this->hidden) && $this->hidden !== FALSE)
       $res .= " style='display:none'";
+    if (isset ($this->cols))
+      $res .= " size='".$this->cols."'";
+    if (isset ($this->errors) || isset ($this->help))
+    {
+      $res .= " aria-describedby='".$this->formName."_";
+      $res .= htmlspecialchars ($this->name, ENT_QUOTES)."_help'";
+    }
     $res .= "/>\n";
     if (isset ($this->errors))
-      $res .= "      <span class='help-block'>".$this->errors[1].
-              "</span>\n";
+    {
+      $res .= "      <span class='help-block' id='$this->formName"."_";
+      $res .= htmlspecialchars ($this->name, ENT_QUOTES)."_help'>".
+              $this->errors[1]."</span>\n";
+    }
+    elseif (isset ($this->help))
+    {
+      $res .= "      <span class='help-block' id='$this->formName"."_";
+      $res .= htmlspecialchars ($this->name, ENT_QUOTES)."_help'>".$this->help
+              ."</span>\n";
+    }
     $res .= "    </div>\n"; // End controls
     $res .= "  </div>\n"; // End form-group
     return $res;