diff --git a/src/includes/class/class.LSattr_html.php b/src/includes/class/class.LSattr_html.php
index d67dabaa..4497da80 100644
--- a/src/includes/class/class.LSattr_html.php
+++ b/src/includes/class/class.LSattr_html.php
@@ -29,11 +29,24 @@ LSsession :: loadLSclass('LSlog_staticLoggerClass');
  */
 class LSattr_html extends LSlog_staticLoggerClass {
 
+  // The attribute name
   var $name;
+
+  // The attribute configuration
   var $config;
+
+  // The reference of the parent LSattribute object
   var $attribute;
+
+  // The corresponding LSformElement object type
   var $LSformElement_type = false;
 
+  // If true, this LSattr_html type is considered as able to only support
+  // the first and unique value of the attribute. If more than one value
+  // is passed to this LSattr_html type, an LSattr_html_03 error will be
+  // triggered.
+  protected $singleValue = false;
+
   /**
    * Constructeur
    *
@@ -94,8 +107,16 @@ class LSattr_html extends LSlog_staticLoggerClass {
       LSerror :: addErrorCode('LSform_06',$this -> name);
       return;
     }
-    if (!is_null($data))
-      $element -> setValue($data);
+    if (!is_null($data)) {
+      $data = ensureIsArray($data);
+      if ($this -> singleValue) {
+        if (count($data) > 1)
+          LSerror :: addErrorCode('LSattr_html_03', get_class($this));
+        $element -> setValue($data[0]);
+      }
+      else
+        $element -> setValue($data);
+    }
     return $element;
   }
 
@@ -144,5 +165,5 @@ ___("LSattr_html : The method addToForm() of the HTML type of the attribute %{at
 );
 // 02 : not yet used
 LSerror :: defineError('LSattr_html_03',
-___("LSattr_html_%{type} : Multiple data are not supported for this field type.")
+___("%{type} : Multiple data are not supported for this field type.")
 );
diff --git a/src/includes/class/class.LSattr_html_image.php b/src/includes/class/class.LSattr_html_image.php
index 3117824b..d1d6e90f 100644
--- a/src/includes/class/class.LSattr_html_image.php
+++ b/src/includes/class/class.LSattr_html_image.php
@@ -27,29 +27,7 @@
  */
 class LSattr_html_image extends LSattr_html {
 
-  /**
-   * Ajoute l'attribut au formualaire passer en paramètre
-   *
-   * @param[in] &$form LSform Le formulaire
-   * @param[in] $idForm L'identifiant du formulaire
-   * @param[in] $data Valeur du champs du formulaire
-   *
-   * @retval LSformElement L'element du formulaire ajouté
-   */
-  function addToForm (&$form, $idForm, $data=NULL) {
-    $element=$form -> addElement('image', $this -> name, $this -> getLabel(), $this -> config, $this);
-    if(!$element) {
-      LSerror :: addErrorCode('LSform_06',$this -> name);
-      return;
-    }
-
-    if ($data && count($data) > 1) {
-      LSerror :: addErrorCode('LSattr_html_03','password');
-    }
-
-    if ($data)
-      $element -> setValue(ensureIsArray($data)[0]);
-    return $element;
-  }
+  var $LSformElement_type = 'image';
+  protected $singleValue = true;
 
 }
diff --git a/src/includes/class/class.LSattr_html_password.php b/src/includes/class/class.LSattr_html_password.php
index 9d32cbcb..2f6e16d6 100644
--- a/src/includes/class/class.LSattr_html_password.php
+++ b/src/includes/class/class.LSattr_html_password.php
@@ -27,29 +27,7 @@
  */
 class LSattr_html_password extends LSattr_html {
 
-  /**
-   * Ajoute l'attribut au formualaire passer en paramètre
-   *
-   * @param[in] &$form LSform Le formulaire
-   * @param[in] $idForm L'identifiant du formulaire
-   * @param[in] $data Valeur du champs du formulaire
-   *
-   * @retval LSformElement L'element du formulaire ajouté
-   */
-  public function addToForm (&$form,$idForm,$data=NULL) {
-    $element = $form -> addElement('password', $this -> name, $this -> getLabel(), $this -> config, $this);
-    if(!$element) {
-      LSerror :: addErrorCode('LSform_06', $this -> name);
-      return;
-    }
-
-    if ($data) {
-      $data = ensureIsArray($data);
-      if (count($data) > 1)
-        LSerror :: addErrorCode('LSattr_html_03', 'password');
-      $element -> setValue($data[0]);
-    }
-    return $element;
-  }
+  var $LSformElement_type = 'password';
+  protected $singleValue = true;
 
 }
diff --git a/src/includes/class/class.LSattr_html_select_object.php b/src/includes/class/class.LSattr_html_select_object.php
index 27c79ce1..6a742150 100644
--- a/src/includes/class/class.LSattr_html_select_object.php
+++ b/src/includes/class/class.LSattr_html_select_object.php
@@ -27,6 +27,7 @@
  */
 class LSattr_html_select_object extends LSattr_html{
 
+  var $LSformElement_type = 'select_object';
   var $unrecognizedValues=false;
 
   /**
@@ -40,7 +41,7 @@ class LSattr_html_select_object extends LSattr_html{
    */
   public function addToForm (&$form,$idForm,$data=NULL) {
     $this -> config['attrObject'] = $this;
-    $element=$form -> addElement('select_object', $this -> name, $this -> getLabel(), $this -> config, $this);
+    $element=$form -> addElement($this -> LSformElement_type, $this -> name, $this -> getLabel(), $this -> config, $this);
     if(!$element) {
       LSerror :: addErrorCode('LSform_06',$this -> name);
       return;