title: MVC 3 JSON call not working in IIS
body: <p>I'm working in an MVC 3 application with ASPX engine and as a point of start I developed a simple search that utilizes a JQuery JSON call to retrieve some info. The call sends a parameter taken from a text input and updates a table with the results. The funcion look like this:</p>
  
  <pre><code>        function PerformLookup() {
              var _accountNumber = $('#accountNumber').val();
  
              $.ajax({
                  url: '/SearchAjax/SearchAccount',
                  type: 'POST',
                  data: '{_accountNumber:'+_accountNumber+'}',
                  dataType: 'json',
                  contentType: 'application/json; charset=utf-8',
                  success: function (data) {
                      UpdateTable(data);
                  },
                  error: function () {
                      alert('An error occurred while performing the search.');
                  }
              });
  
              return false;
          }
  </code></pre>
  
  <p>The server code runs a query with that parameter and returns a list that is serialized to JSON to be worked normally with JQuery.  The server code looks like this:</p>
  
  <pre><code>        [HttpPost]
          public JsonResult SearchAccount(string _accountNumber)
          {
              MLIBEntities dbMLIB = new MLIBEntities();
  
              var searchResults = (from s in dbMLIB.Sets
                                   where s.setmap1 == _accountNumber
                                   select s);
              return Json(searchResults.ToList());
          }
  </code></pre>
  
  <p>As you see it's nothing difficult and it works perfectly when I run the project from VS2010 and use its virtual machine.</p>
  
  <p>The problem happens when I publish the project in a Windows 2008 server with IIS 7. The project runs normally but when I run the PerformLookup function I get the message "An error occurred while performing the search" meaning that the ajax call failed.</p>
  
  <p>Does anyone have any idea why the call is failing in the IIS while working perfectly in the VS2010 virtual machine? Am I missing any configuration IIS wise?</p>
  
  <p>Thanks in advance!</p>