Disable ASP Button on Submit

On the page
private void Page_Init(object sender, EventArgs e)
{
//For ASp.net button
this.btnMoveToMove.Attributes.Add("onclick", "javascript:" + btnMoveToMove.ClientID + ".disabled=true;" + btnMoveToMove.ClientID + ".value= 'please wait...';" + this.GetPostBackEventReference(btnMoveToMove));
For the image button replace the image with other image having text "wait.."
this.ibtnNext.Attributes.Add("onclick", "this.src='/newimg/btns/wait.gif';this.disabled = true;" + this.GetPostBackEventReference(this.ibtnNext));
}