title: jsonp cross domain only working in IE
body: <p><strong>EDIT</strong>: At first I thought it wasn't working cross domain at all, now I realize it only works in IE    </p>
  
  <p>I'm using jQuery to call a web service (<code>ASP.NET .axmx</code>), and trying to us <code>jsonp</code> so that I can call it across different sites.  Right now it is working ONLY in IE, but not in Firefox, Chrome, Safari. Also, in IE, a dialog pops up warning "This page is accessing information that is not under its control..."
  Any ideas? </p>
  
  <p>Here is the code:   </p>
  
  <pre><code>$.ajax({
      type: "POST",
      url: "http://test/TestService.asmx/HelloWorld?jsonp=?",
      dataType: "jsonp",
      success: function(data) {
          alert(data.prop1);
      },
      error: function(XMLHttpRequest, textStatus, errorThrown) {
          alert(XMLHttpRequest.status + " " + textStatus + " " + errorThrown);
      }
  }); 
  </code></pre>
  
  <p>And the server code is:  </p>
  
  <pre><code>[ScriptService]
  public class TestService : System.Web.Services.WebService{
      [WebMethod]
      [ScriptMethod(ResponseFormat = ResponseFormat.Json)]
      public void HelloWorld() {
          string jsoncallback = HttpContext.Current.Request["jsonp"];
          var response = string.Format("{0}({1});", jsoncallback, @"{'prop1' : '" + DateTime.Now.ToString() + "'}");
          HttpContext.Current.Response.Write(response);
      }
  }
  </code></pre>