title: Determine if a callback is in progress (DevExpress)
body: <p>I am looking for a way to determine if any of my DevExpress ASPxGridView controls are currently in a callback state.  I assume those controls use standard ASP.NET callback procedure but I am not sure.  If that is the case there might be an ASP.NET (non-DevExpress) method of determining this.</p>
  
  <p>Specifically, I need to disable a submit button when a callback is occuring because clicking it during a callback causes the page to enter a bad state and give low-level ASP.NET 'Invalid postback or callback argument' event validation errors on future callbacks/submits.</p>
  
  <p>I am using jQuery and the .ajaxSend() and similar global jQuery AJAX methods aren't capturing the callback.</p>
  
  <p>Thank you</p>