function overlay(){
	var left = 0;
	var top = 0;
	var overlaywidth = $(window).width();
	var h = $(window).height()
	var overlayheight = $(document).height();
	if ($.browser.msie) {
	left = document.body.scrollLeft || document.documentElement.scrollLeft;
	top = document.body.scrollTop || document.documentElement.scrollTop;
	}
	else {
	left = window.pageXOffset;
	top = window.pageYOffset;
	}
				
		$('#overlay').css({
						  top:0, 
						  left:0, 
						  width:overlaywidth, 
						  height:overlayheight, 
						  position:"absolute",
						  display:"block",
						  background:'black',
						  opacity:0.7,
						  zIndex:10
					  })
		$('#imglay').css({
						  top:top+h/2, 
						  left:overlaywidth/2-100, 
						  position:"absolute"					 
						 })
}
//type:参数传递的方式，如get,post
//url：要指向的文件的URL
//datastr：要传递的参数串
function showcontainer(type,url,datastr){

	$('select').hide();
	$('body').prepend('<div id="overlay"></div><div id="divcontainer"></div>');
	$('#divcontainer select').show();
	overlay();	
	$.ajax({
		type:type,
		async:false,
		url:url,
		data:datastr,
		success:function(returndata){
			$('#imglay').remove();
			$('#divcontainer').html(returndata);
			showlay();
			},
		error:function(){
			$('#imglay').remove();
			showlay();
			$('#divcontainer').html('有错误，请重新操作！<button onclick="closelay()">关闭</button>');
			}
		});
	showlay();
	$(window).scroll(function(){
			overlay();showlay();
		});
	$(window).resize(function(){
		    overlay();showlay();
		});
		


}
function showlay(){

			var left = 0;
			var top = 0;
			var winWidth = $(window).width();
			var winHeight =  $(window).height();
			var dialogHeight = $("#divcontainer").height();
			var dialogWidth = $("#divcontainer").width();
			
			if ($.browser.msie) {
				left = document.body.scrollLeft || document.documentElement.scrollLeft;
				top = document.body.scrollTop || document.documentElement.scrollTop;
			}
			else {
				left = window.pageXOffset;
				top = window.pageYOffset;
			}
		
			var topOff = top + winHeight/2 - dialogHeight/2;
			var	leftOff =winWidth/2 - dialogWidth/2; 
			var topFixed = topOff - top;
			var	leftFixed = leftOff - left;
			if ($.browser.msie && parseInt($.browser.version) < 7) { 
				$("#divcontainer").css({
												 marginTop:topOff,
												 left:leftOff,
												  position: "absolute",
												  zIndex:200
											  }).show(); 
			}
			else{
				$("#divcontainer").css({
											  marginTop:topFixed,
											  left:leftOff,
											  position: "fixed", 
											  zIndex:200
										  }).show();
			}
		}


function closelay(){
	$('#overlay').remove();
	$('#divcontainer').remove();
	$('select').show();
}