//绑定到HTML文件中的JS通用函数
function addLoadEvent(func){
	var oldonload = window.onload;
	if(typeof window.onload != 'function'){
		window.onload = func;
	}else{
		window.onload = function (){
			oldonload();
			func()
		}
	}
}
//动态添加class代码
function addClass(elem,value){
	if(!elem.className){
		elem.className = value;
	}else{
		newClassName = elem.className;
		newClassName += " ";
		newClassName += value;
		elem.className = newClassName;
	}
}