// Use example:
//	<INPUT TYPE="text" NAME="txtDate" ID="txtDate" SIZE="10" MAXLENGTH="10" onkeydown="date_onkeydown()" VALUE="mm/dd/yyyy">

String.prototype.trim = function () {
	    return this.replace(/^\s*/, "").replace(/\s*$/, ""); 
	    }

String.prototype.padL = function (nLength, sChar) {  
	var sreturn = this;  
	while (sreturn.length < nLength) {
		   sreturn = String(sChar) + sreturn;  
	}  
	return sreturn;
}

function date_onkeydown() {
	if (window.event.srcElement.readOnly) return;
	var key_code = window.event.keyCode;
	var oElement = window.event.srcElement;
	if (window.event.shiftKey && String.fromCharCode(key_code) == "T") {
		var d = new Date();
		oElement.value = String(d.getMonth() + 1).padL(2, "0") + "/" + String(d.getDate()).padL(2, "0") + "/" +
		       d.getFullYear();
		window.event.returnValue = 0;
	}
	
	if (!window.event.shiftKey && !window.event.ctrlKey && !window.event.altKey) {
		if ((key_code > 47 && key_code < 58) ||
		         (key_code > 95 && key_code < 106)) {
            if (key_code > 95) key_code -= (95-47);
            oElement.value = oElement.value.replace(/[mdy]/, String.fromCharCode(key_code));
        }
        if (key_code == 8) {
        	if (!oElement.value.match(/^[mdy0-9]{2}\/[mdy0-9]{2}\/[mdy0-9]{4}$/))
        	    oElement.value = "mm/dd/yyyy";
           oElement.value = oElement.value.replace(/([mdy\/]*)[0-9]([mdy\/]*)$/,  function ($0, $1, $2) {                    var idx = oElement.value.search(/([mdy\/]*)[0-9]([mdy\/]*)$/);                    if (idx >= 5) {                        return $1 + "y" + $2;                    } else if (idx >= 2) {                        return $1 + "d" + $2;                    } else {                       return $1 + "m" + $2;                    }                } );           window.event.returnValue = 0;        }    }    if (key_code != 9) {       event.returnValue = false;    } }