var bg_image_list;
var bg_preload_img=new Array();
var bg_loaded=new Array();
var bg_timer_id;
var bg_renew_id;
var bg_curr_count=0;
var bg_base_href;
var bg_image_id=0;
function theme_bg_preload_image_list(base_href,bg_image_list_str){
	bg_base_href=base_href;
	bg_image_list=bg_image_list_str.split(',');
	bg_load_images();
}
function bg_load_images(){
	var i;
	for(i=0;i<bg_image_list.length;i++){
		bg_preload_img[i]=new Image();
		bg_preload_img[i].src=bg_base_href+bg_image_list[i];
	}
	for(i=0;i<bg_preload_img.length;i++){
		bg_loaded[i]=false;
	}
	bg_timer_id=setInterval("bg_check_load()",250);
	bg_renew_id=setInterval("bg_change_image()",6000);
}
function bg_check_load(){
	var i;
	if (bg_curr_count==bg_preload_img.length){
		clearInterval(bg_timer_id);
		bg_curr_count=0;
		return;
	}
  	for(i=0;i<=bg_preload_img.length;i++){
  		if((bg_loaded[i]==false)&&(bg_preload_img[i].complete)){
  			bg_loaded[i]=true;
  			bg_curr_count++;
  		}
  	}
}

function bg_change_image(){
	bg_image_id++;
	if(bg_image_id>=bg_image_list.length){
		bg_image_id=0;
	}
	document.getElementById('theme_content_div').style.backgroundImage='url('+bg_base_href+bg_image_list[bg_image_id]+')';
}

function bg_stop_renew(){
	bg_image_id=0;
	clearInterval(bg_renew_id);
}