You work as a Web Developer at Certkiller.com. You are in the process of creating a mobile Webapplication. You use Microsoft ASP.NET 3.5 to create the Web application. 
In an assembly named MobileUser the following code exists： 
namespace Certkiller.MobileUser { 
public class Capabilities { 
public static bool IsEnhancedDevice（MobileCapabilities capabilities， string optional） { 
return （capabilities["AJAX"] == Boolean.TrueString && 
capabilities["Silverlight"] == Boolean.TrueString）； 
} 
} 
} 
The following code is contained on a page in the Web application： 
MobileCapabilities capabilities = （MobileCapabilities）Request.Browser； 
bool isEnhancedDevice = capabilities.HasCapability（"SilverlightAndAjax"， null） 
You have to make sure that the code calls the IsEnhancedDevice method of the Capabilities class.You configure the Web.config file to accomplish this.
What should you do？（）

You use Microsoft .NET Framework v3.5 to create a Microsoft ASP.NET application forCertkiller.com. 
The code segment below is written to create a client-script function. （The line numbers is includedfor reference purposes）
1 function updateLabelControl（labelId， newText） {
2 var label = $find（labelId）；
3 label.innerHTML = newText；
4 } 
This newly created script will make use of ASP.NET AJAX. The script will also update the text ofall the Label controls in the web form. It has come to your attention that the Label controls are notupdated when the client script function is tested. However， you receive the"’null’ is null or not anobject" JavaScript error message in the browser. 
What should you do？（）