.Net JS - Register Client Script

/// http://msdn.microsoft.com/en-us/library/kx145dw2%28v=VS.90%29.aspx
String csname = "SpreadJS";
String csurl = "Spread_New_or_All.js";
Type cstype = this.GetType();
ClientScriptManager cs = Page.ClientScript;
if (!cs.IsClientScriptIncludeRegistered(cstype, csname))
{
cs.RegisterClientScriptInclude(cstype, csname, ResolveClientUrl(csurl));
}