//获取样式

function getStyle(obj,attr){

 if(obj.currentStyle){

  return obj.currentStyle[attr];

 }else{

  return getComputedStyle(obj)[attr];

 }

}

//绑定事件

function addHandler(element,type,handler){

 if(element.addEventListener){

  element.addEventListener(type,handler,false);

 }else if(element.attachEvent){

  element.attachEvent("on"+type,handler);

 }else{

  element["on"+type]=handler;

 }

}

//取消绑定事件

function removeHandler(element,type,handler){

 if(element.removeEventListener){

  element.removeEventListener(type,handler,false);

 }else if(element.detachEvent){

  element.detachEvent("on"+type,handler);

 }else{

  element["on"+type]=null;

 }

}

function getById(id){

 id=id+"";

 return document.getElementById(id);

}

function getByClass(obj,className){

 var a=new Array;

 var b=obj.getElementsByTagName("*");

 for(var i in b){

  if(b[i].className==className){

   a.push(b[i]);

  }

 }

 return a;

}