document.onkeydown=function()
{
var EventUtil = {};
EventUtil.getEvent = function(){
if(window.event){return window.event;}
else{return EventUtil.getEvent.caller.arguments[0];}
}
var button = document.getElementById("qw");
if(EventUtil.getEvent().keyCode==13)
{
button.click();
event.returnValue = false;
}
}

window.onkeydown=function()
{
var EventUtil = {};
EventUtil.getEvent = function(){
if(window.event){return window.event;}
else{return EventUtil.getEvent.caller.arguments[0];}
}
　　　　　　//綁定你的id為qw的按鈕事件

var button = document.getElementById("qw");
if(EventUtil.getEvent().keyCode==13)
{
button.click();
event.returnValue = false;
}
}