function swapimg (objid, url)
{
imgobj = document.getElementById(objid);
imgobj.src = url;
}

function preloadimg(imgid)
{
imgobj = document.getElementById('large_img');
imgobj.src = 'img/products/large/' + imgid + '.jpg';
}

function enlargeimg(objid)
{
imgobj = document.getElementById('large_img');
document.getElementById('image_preview').style.display = 'block';
imgobj.src = 'img/products/large/' + objid + '.jpg';
setInterval(500, positionIt('image_preview'));
}

function closeprev()
{
document.getElementById('image_preview').style.display = 'none';
}

positionIt = function(divid) {
	if( document.getElementById ) {
		// Get a reference to divTest and measure its width and height.
		var div = document.getElementById(divid);
		var divWidth = div.offsetWidth ? div.offsetWidth : div.style.width ? parseInt( div.style.width ) : 0;
		var divHeight = div.offsetHeight ? div.offsetHeight :  div.style.height ? parseInt( div.style.height ) : 0;
		
		var vpHeight = getViewportHeight();
		var centerpos = (vpHeight - divHeight) / 2;
		// Calculating setX and setX so the div will be centered in the viewport.
		var setX = 805/2 - divWidth/2;
		var setY = window.scrollY + centerpos;
		// If setX or setY have become smaller than 0, make them 0.
		//if( setX < 0 ) setX = 0;
		//if( setY < 0 ) setY = 0;
		
		// Position the div in the center of the page and make it visible
		
		div.style.left = setX + "px";
		div.style.top = setY + "px";
	}
};

getViewportWidth = function() {
	var width = 0;
	if( document.documentElement && document.documentElement.clientWidth ) {
		width = document.documentElement.clientWidth;
	}
	else if( document.body && document.body.clientWidth ) {
		width = document.body.clientWidth;
	}
	else if( window.innerWidth ) {
		width = window.innerWidth - 18;
	}
	return width;
};

getViewportHeight = function() {
	var height = 0;
	
	if( document.body && document.body.clientHeight ) {
		height = document.body.clientHeight;
	}
	if( window.innerHeight ) {
		height = window.innerHeight - 18;
	}
	return height;
};