oEditor is undefined... : Probleme in JS verification

Hi, im french so sory for my english

I have a big probleme in my back office.

I use PHP,JS and AJAX

I load a FCK editor texte area in basik mode with ajax in my page

the fck editor text area appear: i have 3 fck editor in this page they are loading correctly

whhit this code :

$oFCKeditor = new FCKeditor('evenement_description_courte');
               $oFCKeditor->BasePath = '/fckeditor/';              
               $oFCKeditor->Value = '';
               $oFCKeditor->Create();
$oFCKeditor1 = new FCKeditor('evenement_description');
               $oFCKeditor1->BasePath = '/fckeditor/';              
               $oFCKeditor1->Value = '';
               $oFCKeditor1->Create();
$oFCKeditor2 = new FCKeditor('evenement_lieu');
               $oFCKeditor2->BasePath = '/fckeditor/';              
               $oFCKeditor2->Value = '';
               $oFCKeditor2->Create();