捕获控件的Enter事件

 <script type="text/javascript">
    function conKeyDown()
       {
         if(event.keyCode ==13)
         {
              alert("你摁下了回车");
         }
         event.keyCode   =   9;   //tab
       }
  </script>

<asp:TextBox ID="TextBox1" runat="server"  onkeydown="conKeyDown();" ></asp:TextBox>