function $(_sId)
{return document.getElementById(_sId);}
  
function moveDiv(event, _sId)
{
	var oObj = $(_sId);	
	oObj.onmousemove = mousemove;
	oObj.onmouseup = mouseup;
	oObj.setCapture ? oObj.setCapture() : function(){};
	oEvent = window.event ? window.event : event;
	var dragData = {x : oEvent.clientX, y : oEvent.clientY};
	var backData = {x : parseInt(oObj.style.top), y : parseInt(oObj.style.left)};
   
	function mousemove()
	{
		var oEvent = window.event ? window.event : event;
		var iLeft = oEvent.clientX - dragData["x"] + parseInt(oObj.style.left);
		var iTop = oEvent.clientY - dragData["y"] + parseInt(oObj.style.top);
		oObj.style.left = iLeft;
		oObj.style.top = iTop;
		dragData = {x: oEvent.clientX, y: oEvent.clientY};  
	}
   
	function mouseup()
	{
		var oEvent = window.event ? window.event : event;
		oObj.onmousemove = null;
		oObj.onmouseup = null;
		if(oEvent.clientX < 1 || oEvent.clientY < 1)
		{
			oObj.style.left = backData.y;
			oObj.style.top = backData.x;
		}
			oObj.releaseCapture ? oObj.releaseCapture() : function(){};
	}
}

function closeDiv(_sID)
{
	var oObj = $(_sID);
	var overlay = $("overlay");	
	if(overlay != null)
	{
		overlay.outerHTML = "";
	}
	oObj.style.display = "none";
	
}

function showDiv(_sID,event)
{
	var arrySize = getPageSize();
	var oObj = $(_sID);
	//创建一个DIV,改名为 overlay 这个是透明的层	
	var oDiv =document.createElement("div");
	oDiv.id = "overlay";
	document.body.appendChild(oDiv);
	var overlay = $("overlay");
	overlay.style.height = arrySize[1];
	overlay.style.width = arrySize[0];
	//alert(arrySize[1]);	
	if(event == null)
	{
		if(oObj.style.left == "")
		{
			oObj.style.left = arrySize[0] / 2 - 150 ;
		}
		
		if(oObj.style.top == "")
		{
			oObj.style.top =  arrySize[0] / 2;
		}		
	}
	else
	{		
		var iEvent= window.event ? window.event : event;		
		oObj.style.left = arrySize[0] / 2 - 150 ; // iEvent.clientX;
		oObj.style.top = arrySize[1] / 2 - 150 ;// iEvent.clientY;
		
	}
	
	oObj.style.display = "block";
	overlay.style.display = "block";
	overlay.style.zindex = oObj.style.zindex - 1;
}

//取得页面大小
function getPageSize(){
	
	var xScroll, yScroll;
	
	if (window.innerHeight && window.scrollMaxY) {	
		xScroll = document.body.scrollWidth;
		yScroll = window.innerHeight + window.scrollMaxY;
	} else if (document.body.scrollHeight > document.body.offsetHeight){ // all but Explorer Mac
		xScroll = document.body.scrollWidth;
		yScroll = document.body.scrollHeight;
	} else { // Explorer Mac...would also work in Explorer 6 Strict, Mozilla and Safari
		xScroll = document.body.offsetWidth;
		yScroll = document.body.offsetHeight;
	}
	
	var windowWidth, windowHeight;
	if (self.innerHeight) {	// all except Explorer
		windowWidth = self.innerWidth;
		windowHeight = self.innerHeight;
	} else if (document.documentElement && document.documentElement.clientHeight) { // Explorer 6 Strict Mode
		windowWidth = document.documentElement.clientWidth;
		windowHeight = document.documentElement.clientHeight;
	} else if (document.body) { // other Explorers
		windowWidth = document.body.clientWidth;
		windowHeight = document.body.clientHeight;
	}	
	
	// for small pages with total height less then height of the viewport
	if(yScroll < windowHeight){
		pageHeight = windowHeight;
	} else { 
		pageHeight = yScroll;
	}

	// for small pages with total width less then width of the viewport
	if(xScroll < windowWidth){	
		pageWidth = windowWidth;
	} else {
		pageWidth = xScroll;
	}


	arrayPageSize = new Array(pageWidth,pageHeight,windowWidth,windowHeight) 
	return arrayPageSize;
}