不知道为什么不能运行，求解答
var eventUntil={
addHandler:function(element,type,handler){
if(element.addEventListener){
element.addEventListener(type,handler,false);
}else if(element.attchEvent){
element.attchEvent('on'+type,handler);
}else{
element['on'+type] = handler;
}
},
eventHandler:function(element,type,handler){
if(element.removeEventListener){
element.removeEventListener(type,handler,false);
}else if(element.detachEvent){
element.detachEvement('on'+type,handler);
}else{
element['on'+type] = handler;
}
}
}
var btn5 = document.getElementById("btn5");
eventUntil.addHandler(btn5,'click',four);
