//========[preload_image]
var image1=new Image(); image1.src='images/photo_albums/1/1_big.jpg';         
var image2=new Image(); image2.src='images/photo_albums/1/2_big.jpg';     
var image3=new Image(); image3.src='images/photo_albums/1/3_big.jpg';     
var image4=new Image(); image4.src='images/photo_albums/1/4_big.jpg';     
//========[/preload_image]

function photo_change(id1,num) {
	document.getElementById(id1).style.backgroundImage= "url(images/photo_albums/1/"+num+"_big.jpg)";
}