detectKeyPress.js

/*
* 判斷按下的按鈕是哪一個
 * @param (event) 		e               keypress event.
 * @param (mix) 		targetKeyChar   按鍵的編號或名稱，如果是這個按鍵，就執行 callback
 * @param (function) 		callBack        送入callback的function，不用加()括號
 *
 */
 
var detectKeyPress = function(e, targetKeyChar, callBack){
	var keynum
	var keychar
	var numcheck
	
	if(window.event) // For IE
	{
		keynum = e.keyCode
		
	}else if(e.which) // For Netscape/Firefox/Opera
	{
		keynum = e.which
	}
	
	keychar = String.fromCharCode(keynum)
	
	if( typeOf(targetKeyChar) == 'string' ) {
		if(targetKeyChar == keychar) {
			callBack() ;
		}
	}else{
		if(targetKeyChar == keynum) {
			callBack() ;
		}
	}
}

使用方式.html

<input onkeypress="detectKeyPress(event, 'a', callBackFunction );" />