var gw;
var gh;

function initGallery() {

if (window.innerWidth) {
 gw = window.innerWidth;
}    else if (document.documentElement && document.documentElement.clientWidth)    {
 gw = document.documentElement.clientWidth;
}    else if (document.body)    {
 gw = document.body.clientWidth;
}
if (window.innerHeight) {
 gh = window.innerHeight;
}    else if (document.documentElement && document.documentElement.clientHeight)    {
 gh = document.documentElement.clientHeight;
}    else if (document.body)    {
 gh = document.body.clientHeight;
}

}


function show(id) {
	mypicdiv = document.getElementById(id);
	var popheight = mypicdiv.style.height;
	var popwidth = mypicdiv.style.width;
	var poptop = Math.round((gh - popheight.substr(0,3)) / 2 - 20);
	var popleft = Math.round((gw - popwidth.substr(0,3)) / 2);
	
	mypicdiv.style.top = poptop+'px';
	mypicdiv.style.left = popleft+'px';
	mypicdiv.style.display = "block";
	
}
function hide(id) { 
	document.getElementById(id).style.display = "none";
}