var temp = new Image();
var loc;
var loaded = 0;

function checkme()
{
	var count = 0;
	var j = new Array("a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p");
	var jname = new Array("pic1","pic2","pic3","pic4","pic5","pic6","pic7","pic8","pic9","pic10","pic11","pic12","pic13","pic14","pic15","pic16");
	for (n=0;n<16;n++)
	{
	if(document.images[jname[n]].src == "http://www.jmbt.org.uk/coin/coin" + j[n] + ".jpg")
		{
		count++;
		if(count == 15)
			{
			document.getElementById("puzzle").style.border = "5px #963 solid";
			alert("Well done! You've completed the puzzle!");
			}
		}
	}
}

function exch(imageName)
{
if (document.getElementById)
	{
		if (loaded==1)
		{
		loaded=0;
		document.images[loc].src = document.images[imageName].src;
		document.images[imageName].src = temp.src;
		checkme();
		}
		else
		{
		loaded=1;
		document.images[loc] = document.images[imageName];
		temp.src=document.images[imageName].src;
		}
	}
}