网页内按回车触发

function document.onkeydown() //网页内按下回车触发
{
if(event.keyCode==13)
{
document.getElementById("Button").click();
return false;
}
}

/*********************************************************

<script type="text/javascript">

document.onkeydown=ShowEnterKey;

if (event.keyCode==13)
{

event.keyCode=0;
event.returnValue = false;

alert("hhaha");
}

}

</script>