C# - Protect Application To Run Only On Specified Domain?

I'm going to publish an asp.net pre-compiled web site on shared hosting account but I don't want my code to be copied and able to run on another domain. I need to check domain and if not example.com or www.example.com redirect to error page or show error as response.

EDIT: Here is my solution based on given answers

void Application_BeginRequest(object sender, EventArgs e)
{
string[] safeDomains = new string[] { "localhost",
"example.com", "www.example.com" };
if (!((IList)safeDomains).Contains(Request.ServerVariables["SERVER_NAME"]))
{
Response.Write("Domain not allowed!");
Response.End();
}
}