Yes & No button in java script alert?

use like as in below link using modal popup

http://www.aspsnippets.com/Articles/Confirmation-Confirm-box-with-Yes-No-Buttons-Options-using-AJAX-Modal-Popup-Extender-in-ASPNet.aspx

or


use
onpage_load
{
  btndelete.Attributes.Add("onclick", "javascript:if(confirm('Are you sure you want to delete?'))return true; else return false;")
}

Hello

You can use below code