how to write a progrmme for open the pages in website when user type the page names in url using asp.net

ex:www.buddiesdesk.com/raju.aspx;whenever we type the raju in url automatically display the his profile using userid
I have some code using global.asax.i dont know its correct or not
void Application_Start(object sender, EventArgs e)
    {

        string path = HttpContext.Current.Request.PhysicalApplicationPath + "usprofile.aspx";
        if (File.Exists(Request.PhysicalPath))
        {
            
        }
        else if (!File.Exists(Request.PhysicalPath))
        {


            string requrl = Request.Path.Replace("usprofile.aspx", "");
...