//验证码
function UpdateCode(imgName){
	objImg = document.getElementById(imgName);
	var src = objImg.src;	
	var oRandom = Math.random() * 1000;
	re = /changeId=\d{3}/;
	arr = re.exec(src);
	if(arr == null){
		src += "?changeId=" + oRandom;
	}
	else{
		src = src.replace(src.substr(arr.index,13),"changeId=" + oRandom);	
	}
	objImg.src = src;
}