这里的变量为什么取不到值

Question

function fnDown(event) {
	event=event||window.event;
	var loginPanel=document.getElementById('loginPanel');
		disX =event.clientX-loginPanel.offsetLeft;
		disY = event.clientY-loginPanel.offsetTop;

	document.onmousemove=function(event){
		event=event||window.event;
		var changedisX=event.clientX-disX,
			changedisY=event.clientY-disY,
			winW=document.documentElement.clientWidth||document.body.clientWidth,
			winH=document.documentElement.clientHeight||document.body.clientHeight,
			maxW=winW-loginPanel.offsetWidth,// loginPanel 不可以从fnDown()取得值吗?
			maxH=winH-loginPanel.offsetHeight;			
		if (changedisX<0) {
			changedisX=0;
		}else if (changedisX>maxW) {
			changedisX=maxW;
		}
		loginPanel.style.left=changedisX+"px";
		loginPanel.style.top=changedisY+"px";
	}
	document.onmouseup=function(){
		document.onmousemove=null;
		document.onmoseup=null;
	}
	// body...
}

Answer 1

可以的