title: Telerik RadScriptManager - error while combining js files
body: <p>I'm trying to combine multiple js file references using Telerik's script manager.  Here is the code I have on page load:</p>
  
  <pre><code>        System.Web.UI.ScriptReference jsFile1 = new System.Web.UI.ScriptReference('/virtual_folder/jsfile1.js');
          System.Web.UI.ScriptReference jsFile2 = new System.Web.UI.ScriptReference('/virtual_folder/jsfile2.js');
  
  
          this.Master.ScriptManager.CompositeScript.Scripts.Add(jsFile1);
          this.Master.ScriptManager.CompositeScript.Scripts.Add(jsFile2);
  </code></pre>
  
  <p>I'm getting an error:</p>
  
  <p>[NullReferenceException: Object reference not set to an instance of an object.]
     System.Collections.ObjectModel.Collection`1.Add(T item) +18</p>
  
  <p>Telerik.Web.UI.RadScriptManager.Page_PreRenderComplete(Object sender, EventArgs e) +95</p>
  
  <p>System.EventHandler.Invoke(Object sender, EventArgs e) +0</p>
  
  <p>System.Web.UI.Page.OnPreRenderComplete(EventArgs e) +8695102</p>
  
  <p>System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +1029</p>
  
  <p>What am I doing wrong?</p>