<input type="text" onkeydown="keyNumAll(event);" >

function keyNumAll(evt){
//兼容IE和Firefox獲得keyBoardEvent對象
evt = (evt) ? evt : ((window.event) ? window.event : "");
var key = evt.keyCode?evt.keyCode:evt.which;//兼容IE和Firefox獲得keyBoardEvent對象的鍵值
console.info(key);//顯示按鍵鍵值
}
}