Objective:- From the server-side, I need to open a radwindow(defined in JavaScript of the aspx page) automatically on an IF condition.
Code
Take a look here, it explains how to use the ScriptManager.RegisterStartupScript method: http://www.telerik.com/help/aspnet-ajax/window-troubleshooting-javascript-from-server-side.html. Note it the ScriptManager's method. Also look at the Sys.Application.Load event to prevent your code from executing too early.