diff --git a/htdocs/core/lib/ajax.lib.php b/htdocs/core/lib/ajax.lib.php
index acf7aa326e6..0193a33b305 100644
--- a/htdocs/core/lib/ajax.lib.php
+++ b/htdocs/core/lib/ajax.lib.php
@@ -356,6 +356,7 @@ function ajax_dialog($title,$message,$w=350,$h=150)
  * @param	array	$events						More events option. Example: array(array('method'=>'getContacts', 'url'=>dol_buildpath('/core/ajax/contacts.php',1), 'htmlname'=>'contactid', 'params'=>array('add-customer-contact'=>'disabled')))
  * @param  	int		$minLengthToAutocomplete	Minimum length of input string to start autocomplete
  * @param	int		$forcefocus					Force focus on field
+ * @param	string	$widthTypeOfAutocomplete	'resolve' or 'off'
  * @return	string								Return html string to convert a select field into a combo, or '' if feature has been disabled for some reason.
  */
 function ajax_combobox($htmlname, $events=array(), $minLengthToAutocomplete=0, $forcefocus=0, $widthTypeOfAutocomplete='resolve')