title: How to make controls from ajax control toolkit work in project upgraded from VS2008 to VS2010
body: <p>I had a working project in VS2008 / .Net 3.5 using controls from the ajax control toolkit (which targets .Net 3.5).</p>
  
  <p>I upgraded the project in VS2010 Beta 2.  I chose to target .Net 4.0 so I could take advantage of routing for WebForms (which is working).</p>
  
  <p>When a page with a ModalPopupExtender loads, however, I get errors, "Syntax error" referencing a URI like:<br>
  {localhost}/WebResource.axd?d=-sR5kj2yKK777ENh8pDLSA2&amp;t=633960551687981257.<br>
  Then the page loads incorrectly because the necessary javascript files failed to load.</p>
  
  <p>I tried downloading the new control toolkit from ajax.codeplex.com and referencing the AjaxControlToolkit.dll within, clearing out temporary files for framework 2.0 &amp; 4.0, but it made no difference.</p>
  
  <p>I then read <a href="http://codeimpossible.com/2009/04/24/debugging-syntax-error-from-a-bad-webresourceaxd-request/" rel="nofollow noreferrer">this post</a> about further debugging the error.  When I decrypted the requests to WebResource.axd, they showed paths that looked like yay:</p>
  
  <ul>
  <li>s|WebForms.js</li>
  <li>ZSystem.Web,4.0.0.0,,b03f5f7f11d50a3a|WebUIValidation.js|</li>
  </ul>
  
  <p>So pipe delimited references to files seem to have been constructed incorrectly.  It seems unlikely anyone would have any idea what to do about this, but what the heck...</p>