XXX is not a function

如题，做了个绑定邮箱的页面

function bindAJAX(){
	try{
		return new XMLHttpRequest();
	}catch(e){
		try{
			return new ActiveXObject("Msxm12.XMLHTTP");
		}catch(e){
			try{
				return new ActiveXObiect();
			}catch(e){
				return "请求成功";
			}
		}
	}
}
var bindEML=bindAJAX();
var url="http://127.0.0.1:8000/";
var params="username&password&email";
bindEML.open("POST",url,true);
bindEML.setRequestheader("Content-type","application/x-www-form-urlencoded");
bindEML.send(params);
bindEML.onreadystatechange=function(){
	if(bindEML.readyState==4){
		if(bindEML.status==200){
			alert(bindEML.msg);
		}
		else{
			alert(bindEML.msg);
		}
	}
}

报错内容：

UncaughtTypeError: bindEML.setRequestheader is not a function

求大佬指教

bindAJAX 里面的分支加下日志，看返回的是哪个，那个类有这个方法么？

setRequestHeader 单词大小写错误