function launch_popup(filename, mw, mh) {
	var ox = mw+17;
	var oy = mh+19;
	if((ox>=screen.width) || (oy>=screen.height)){
		var ox = screen.width-150;
		var oy = screen.height-150;
		var winx = (screen.width / 2)-(ox / 2);
		var winy = (screen.height / 2)-(oy / 2);
		var use_scrollbars = 1;
	}
	else{
		var winx = (screen.width / 2)-(ox / 2);
		var winy = (screen.height / 2)-(oy / 2);
		var use_scrollbars = 0;
	}
	var win = window.open('http://www.uklakes.net/images/userphotos/full/' + filename, 'imagev', 'height='+oy+'-10,width='+ox+',top='+winy+',left='+winx+',scrollbars='+use_scrollbars+',resizable');
}