function vMiddle(){    var middleDiv=document.getElementById("wrap");    var divHeight=middleDiv.offsetHeight;   var bodyHeight=document.body.offsetHeight ;    if(bodyHeight>divHeight)      middleDiv.style.marginTop=-divHeight/2+"px";   else{     middleDiv.style.marginTop=0;     middleDiv.style.top=0;    }}


$(function(){
	vMiddle();
	})
// JavaScript Document