Page_load(object obj,EventArgs e)
{
if(!IsPostBack)
{
if(Request.UrlReferrer!=null) //
{
ViewState["UrlReferrer"]=Request.UrlReferrer.ToString();
}
}
}

void Return()
{
if(ViewState["UrlReferrer"]!=null)
Response.Redirect(ViewState["UrlReferrer"].ToString();
}