//initialisation
var preLoad = new Array();
var p = 2;

for (i = 0; i < p; i++) {
	preLoad[i] = new Image();
		var img_id = "img" + i;
		var img = document.getElementById(img_id);
			preLoad[i].src = img.src;
}

//function to change images
function change_image(direction)
{
	var div_id = "image_div";
	var image_id = "saveourpubs_img";
	
	var speed = 1;
	
	if (direction == 'over')
	{
		var timer = 0;
		
		var div = document.getElementById(div_id);
		var img = document.getElementById(image_id);
		
		//set the current image as background 
		div.style.backgroundImage = "url(" + preLoad[0].src + ")";
		
		//make image transparent 
		changeOpac(0, image_id);
		
		//make new image
		img.src = preLoad[1].src;
		
		//fade image in
		for(i = 0; i <= 100; i++)
		{ 
			setTimeout("changeOpac(" + i + ",'" + image_id + "')",(timer * speed)); 
			timer++;
		}
	}
	else if (direction == 'back')
	{
		var timer = 0;
		
		var div = document.getElementById(div_id);
		var img = document.getElementById(image_id);
		
		//set the current image as background 
		div.style.backgroundImage = "url(" + preLoad[1].src + ")";
		
		//make image transparent 
		changeOpac(0, image_id);
		
		//make new image
		img.src = preLoad[0].src;
		
		//fade image in
		for(i = 0; i <= 100; i++)
		{ 
			setTimeout("changeOpac(" + i + ",'" + image_id + "')",(timer * speed)); 
			timer++;
		} 
	}
}

//change the opacity for different browsers 
function changeOpac(opacity, image_id) {
	var img = document.getElementById(image_id);
    img.style.opacity = (opacity / 100); 
    img.style.MozOpacity = (opacity / 100); 
    img.style.KhtmlOpacity = (opacity / 100); 
    img.style.filter = "alpha(opacity=" + opacity + ")"; 
}