var bt06=document.getElementById("bt6");

var eventUtil={

//添加句柄

addHandler:function(element,type,handler){ //type事件类型例如：onclick

if(element.addEventListener){

element.addEventListener(type,handler,false);//触发handler操作（冒泡阶段）

}else if(element.attachEvent){

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

}else{

element['on'+type]=handler;//element.onclick===element['onclick']

}

}

//删除句柄

removeHandler:function(element,typt,handler){

if(element.removeEventListener){

element.removeEventListener(type,handler,false);

}else if(element.detachEvent){

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

}else{

element['on'+type]=null;

}

}

}

eventUtil.addHandler(bt06,'click',showMes);

eventUtil.removeHandler(bt06,'click',showMes);