function $d(element){
	if(arguments.length>1){
		for(var i=0,elements=[],length=arguments.length;i<length;i++)
			elements.push($d(arguments[i]));
		return elements;
	}
	if(typeof element=="string")
		return document.getElementById(element);
	else
		return element;
}
var Class={
	create:function(){
		return function(){
			this.initialize.apply(this,arguments);
		}
	}
}
//判断为空
function empty(obj){
	obj=$d(obj);
	return obj.value.replace(/(^\s+)|(\s+$)/g,"").length>0?false:true;	
}
function trim(str){
	return str.replace(/(^\s+)|(\s+$)/g,"");
}
//获取类
document.getElementsByClassName=function(className,parentElement,tagName) {
    var children = ($d(parentElement)||document.body).getElementsByTagName(tagName||'*');
    var elements = [],child;
    for (var i=0,length=children.length;i<length;i++) {
      child = children[i];
      if (hasClassName(child,className))
        elements.push(child);
    }
    return elements;
};
//判断对象element是否包含指定类className
function hasClassName(element,className) {
	if (!(element=$d(element))) return false;
	var elementClassName=element.className;
	if (elementClassName.length == 0) return false;
	if (elementClassName==className||elementClassName.match(new RegExp("(^|\\s)"+className+"(\\s|$)")))
		return true;
	return false;
}
/*
<form onsubmit="formValid(this);return false;" method="post" url="http://www.baidu.com/" des="留言成功" action="#vapour">
url表示表单提交后，要跳转的地址
des表示表单提交成功后，弹出提示语

<input type="text" class="valid" des="姓名不能为空" />
*/
function formValid(form){
	var arrValid=document.getElementsByClassName("valid",form);
	for(var i=0,length=arrValid.length;i<length;i++){
		if(empty(arrValid[i])){
			alert(arrValid[i].getAttribute("des")||"选项不能为空");	
			arrValid[i].value="";
			arrValid[i].focus();
			return false;
		}else{
			if(!arrValid[i].getAttribute("pattern")) continue;
			var reg=new RegExp(arrValid[i].getAttribute("pattern"),"");
			if(!reg.test(arrValid[i].value)){
				alert("格式不正确");
				arrValid[i].focus();
				arrValid[i].select();
				return false;
			}
		}
	}
	form.submit();
	alert(form.getAttribute("des")||"留言成功,点击返回");
	window.location=form.getAttribute("url")||"/";
}