Introduction:
In this article,explains how to avoid submitting buttonclick more than once.

Main:
sometimes we clicked the web button more than once wrongly,simply its a careless mistake, but it will create a huge impact
in business perspective.

We can easily avoid this using the below simple technique,

Step 1:

I am setting the datetime in session variable at pageload,

Session["IsPageReady"] = Server.UrlEncode(System.Datetime.Now.ToString());

Step 2:

We allready know,while refreshing page it will reach prerender,so iam going to set Session["IsPageReady"] into viewstate at page prerender,

ViewState["IsPageReadyl"] = Session["IsPageReady"].ToString();

Step 3:

In buttonclick,

if(Session["IsPageReady"].ToString() == ViewState["IsPageReadyl"].ToString()) { Response.Write("Page allready Refreshed"); return 0; } else { ViewState["IsPageReadyl"] = Session["IsPageReady"].ToString();   //Continue yours coding part }

Conclusion:
Hope this helps,
Happy Coding.