var currentX = 0;
var currentY = 0;
var whichIt = null;
//判断当前浏览器的版本
var NS = (document.layers) ? 1 : 0;	
var IE = (document.all) ? 1 : 0;
// 函数grabIt,moveIt,dropIt的功能：拖动浮动层
function grabIt(nameIt,e){
	if(IE){
	whichIt = event.srcElement;
	while (whichIt.id.indexOf(nameIt) == -1){
	whichIt = whichIt.parentElement;
	if(whichIt == null) return true;
	}
	whichIt.style.pixelLeft = whichIt.offsetLeft;
	whichIt.style.pixelTop = whichIt.offsetTop;
	currentX = (event.clientX + document.body.scrollLeft);
	currentY = (event.clientY + document.body.scrollTop);
	}
	else{
	window.captureEvents(Event.MOUSEMOVE);
		if(checkFocus (e.pageX,e.pageY)){
		whichIt = eval("document."+nameIt);
		StalkerTouchedX = e.pageX - eval("document."+nameIt).pageX;
		StalkerTouchedY = e.pageY - eval("document."+nameIt).pageY;
		}
	}
	return true;
}

function moveIt(e){
	if(whichIt == null) return false;
	if(IE){
	newX = (event.clientX + document.body.scrollLeft);
	newY = (event.clientY + document.body.scrollTop);
	distanceX = (newX - currentX);
	distanceY = (newY - currentY);
	currentX = newX;
	currentY = newY;
	whichIt.style.pixelLeft +=distanceX;
	whichIt.style.pixelTop +=distanceY;
	if(whichIt.style.pixelTop < document.body.scrollTop) whichIt.style.pixelTop = document.body.scrollTop;
	if(whichIt.style.pixelLeft < document.body.scrollLeft) whichIt.style.pixelLeft = document.body.scrollLeft;
	if(whichIt.style.pixelLeft > document.body.offsetWidth - document.body.scrollLeft - whichIt.style.pixelWidth -20) 
		whichIt.style.pixelLeft = document.body.offsetWidth - whichIt.style.pixelWidth - 20;
	if(whichIt.style.pixelTop > document.body.offsetHeight + document.body.scrollTop - whichIt.style.pixelHeight -5)
		whichIt.style.pixelTop = document.body.offsetHeight + document.body.scrollTop - whichIt.style.pixelHeight - 5;
	event.returnValue = false;
	}
	else{
	whichIt.moveTo(e.pageX - StalkerTouchedX,e.pageY - StalkerTouchedY);
	if(whichIt.left < 0 + self.pageXOffset) whichIt.left = 0 + self.pageXOffset;
	if(whichIt.top < 0 + self.pageYOffset) whichIt.top = 0 + selt.pageYOffset;
	if((whichIt.left + whichIt.clip.width) >= (window.innerWidth + self.pageXOffset - 17))
		whichIt.left = ((window.innerWidth + self.pageXOffset) - whichIt.clip.width) -17;
	if((whichIt.top + whichIt.clip.height) >= (window.innerHeight + self.pageYOffset - 17))
		whichIt.top = ((window.innerHeight + self.pageYOffset) -whichIt.clip.height) - 17;
	return false;
	}
	return false;
}

function dropIt(){
	whichIt = null;
	if(NS) window.releaseEvents(Event.MOUSEVE);
	return true;
}