asp.net 设置命令按钮的快捷键为Enter

using System;
using System.Collections;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;

public partial class _Default : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        TextBox1.Attributes.Add("onkeydown",
       "if(event.which || event.keyCode){if ((event.which == 13) || (event.keyCode == 13)) {document.getElementById('" + Button1.UniqueID + "').click();return false;}} else {return true}; ");
    }
    protected void Button1_Click(object sender, EventArgs e)
    {
        Response.Write("<script>alert('你设置了回车键Enter');</script>");     
    }
}