<!--

var lu = new Array(16)

var hole=15

var holeImage="puzzle_pieces/hole.gif"

function init()
{
	for ( var i = 0 ; i < document.images.length ; i ++ ) {
		for (var j = 0 ; j < 16 ; j++ ) {
			if ( document.images[i].name == "pos" + j) {
				lu[j]=i
			}
		}
	}
}

function swap(h,t1)
{
	h=lu[h]
	t=lu[t1]
	document.images[h].src=document.images[t].src
	document.images[t].src=holeImage
	hole=t1
}

function move(tile)
{
	var distance=hole-tile
	if ( distance<0 ) distance = -(distance)
	if ( distance==1 || distance==4 ) {
		swap(hole,tile)
	};
}

function scramble()
{
	for (var i=0; i < 128; i++ ) {
		var r = Math.random()
	
		if ( r < 0.5 ) {	//move H
			var h = hole % 4
			if ( h == 0 || ( r < 0.25 && h != 3 ) )
				t=hole+1
			else
				t=hole-1
		}
		else {
			var h = Math.floor( hole / 4 )
			if ( h == 0 || ( r < 0.75 && h != 3 ) )
				t=hole+4
			else
				t=hole-4
		}
		
		swap(hole,t)
	}
}

// -->