telnet and web service problem

[fguihen]

hi all. starting to investigate these web services. i have the simple hello world service created. its deployed to IIS. when i try to telnet

"telnet localhost 80" thats fine.
i set the local echo so that i can see whats going on.
i try to use HTTP GET like this:
"GET /WebService1/Service1.asmx/HelloWorld HTTP/1.1"

it says this is an invalid command. im going mad. i have checked spelling mistakes, and loads of stuff and i cant telnet my service. any ideas?

heres the service. not much i know:

public class Service1 : System.Web.Services.WebService
	{
		public Service1()
		{
			
			InitializeComponent();
		}
		[WebMethod]
		public string HelloWorld()
		{
			
			return "Hello World" ;
		}
	}