Asp.net防止页面被多次提交

< script language = " javascript " >
         <!--
        
         function  disableOtherSubmit()
        {             var  obj  =  event.srcElement;
             var  objs  =  document.getElementsByTagName('INPUT');
             for ( var  i = 0 ; i < objs.length; i ++ )
            {
                 if (objs[i].type.toLowerCase()  ==  'submit')
                {
                    objs[i].disabled  =   true ;
                }
            }        }
            
         // -->
         </ script >

public   class  PreventMultiClick : System.Web.UI.Page
    {
         protected  System.Web.UI.WebControls.Button Button1;
         protected  System.Web.UI.WebControls.Button Button2;
         protected  System.Web.UI.WebControls.LinkButton LinkButton1;
         protected  System.Web.UI.WebControls.Button Button3;
    
         private   void  Page_Load( object  sender, System.EventArgs e)
        {
             this .GetPostBackEventReference( this .Button3);         // 保证 __doPostBack(eventTarget, eventArgument) 正确注册
             if ( ! IsPostBack)
            {
                System.Text.StringBuilder sb  =   new  System.Text.StringBuilder();
                sb.Append( " if (typeof(Page_ClientValidate) == 'function') { if (Page_ClientValidate() == false) { return false; }} " );     // 保证验证函数的执行
                sb.Append( " if(window.confirm('are you sure?')==false) return false; " );         // 自定义客户端脚本
                sb.Append( " disableOtherSubmit(); " );         //  disable所有submit按钮
                sb.Append( this .GetPostBackEventReference( this .Button3));     // 用__doPostBack来提交，保证按钮的服务器端click事件执行
                sb.Append( " ; " );
                Button3.Attributes.Add( " onclick " ,sb.ToString());
            }
        }

         #region  Web Form Designer generated code
         override   protected   void  OnInit(EventArgs e)
        {
             //
             //  CODEGEN: This call is required by the ASP.NET Web Form Designer.
             //
            InitializeComponent();
             base .OnInit(e);
        }
        
         ///   <summary>
         ///  Required method for Designer support - do not modify
         ///  the contents of this method with the code editor.
         ///   </summary>
         private   void  InitializeComponent()
        {    
             this .Button3.Click  +=   new  System.EventHandler( this .Button3_Click);
             this .Load  +=   new  System.EventHandler( this .Page_Load);

        }
         #endregion

         private   void  Button3_Click( object  sender, System.EventArgs e)
        {
            System.Threading.Thread.Sleep( 3000 );
            Response.Write( " Hello world! " );
        }
    }