System.NullReference Exception

[Rama Jayapal]

i have written the following code to call a method in a class like

in the aspx.cs page
List<string> surls = new List<string>();

Cweb.GetMainUrls(document,ref surls);
Response.Write(surls);


in the Cweb Class page the coding is like

public static void GetMainUrls(Htmldocument doc,ref List<string> urls)
{
//Some functionalities
}

i get the following error when i run the application like

System.NullReference Exception
object reference not set to an instance

so because of this error my method is not getting called from the class and hence no result

can anyone help me out in finding like why my method was not called

i google through several sites and found that
this may be due to the fact that the "surls" are null and hence the method was not called
i dont follow these sequence

so anybody plz help me on this regard
thanks
Rama

[Motoma]

This exception is probably being thrown inside GetMainUrls(). Put a check in place the handle a null value for urls, and initialize any null strings inside urls before proceeding with the function.