var imageWin = null;
function showFullSize(image_src){
	var w = screen.width;
	var h = screen.height;
	var window_width = 762;
	var window_height = 600;
	var wx = (w - window_width)/2;
	var wy = (h - window_height)/2;
	
	if(imageWin != null){
		imageWin.close();
	}
	imageWin = null;
	imageWin = window.open(
		"image.php?img_src=" + image_src, 
		"imageWindow", 
		"titlebar=yes, toolbar=yes, addressbar=no, menubar=no, status=no, directories=no, resizable=yes, scrollbars=yes, top=" + wy.toString() + ", left=" + wx.toString() + ", width=" + window_width.toString() + ", height=" + window_height.toString() + ""
	);
	while(imageWin==null);
	imageWin.focus();
}