Attache form to tab AJAX not validate

Dear Support Team!

I load simple html to tab page.

tabbar.setHrefMode("ajax-html");
tabbar.setContentHref(full_id,"http://localhost/infobase_web/index.php/"+id.toLowerCase());

the page contain dhtmlXForm component.The validating not working nothing happaen.

<style>
.dhxlist_obj_dhx_skyblue label{
    color:#000000;
    font-family:Tahoma;
    font-size:11px;
}
.dhxlist_obj_dhx_skyblue .dhxlist_txt_textarea, input.dhtmlx_validation_error{
    border: 1px solid #A4BED4;
    padding: 1px 0;
}
</style>
 <form action="" method="post" accept-charset="utf-8" id="my_form">
    <label>User name: </label><input class="dhxlist_txt_textarea" validate="NotEmpty" type="text" name="user_name" value="" />
    <label>Email: </label><input class="dhxlist_txt_textarea" validate="ValidEmail" type="text" name="user_name" value="" />
    <input type="button" command="validate" value="Validate" />
</form>
<script>new dhtmlXForm("my_form");</script>

what is wrong ?

Thanks for your help.

Please check the post viewtopic.php?f=4&t=18027