var bg_images = new Array(); 
 //all the images in a list.  Woot.
 bg_images[0] = 'images/hidden_art/1.jpg';
 bg_images[1] = 'images/hidden_art/2.jpg';
 bg_images[2] = 'images/hidden_art/3.jpg';
 bg_images[3] = 'images/hidden_art/4.jpg';
 bg_images[4] = 'images/hidden_art/5.jpg';  
 bg_images[5] = 'images/hidden_art/6.jpg';
 bg_images[6] = 'images/hidden_art/7.jpg';
 bg_images[7] = 'images/hidden_art/8.jpg';
 bg_images[8] = 'images/hidden_art/9.jpg';
 bg_images[9] = 'images/hidden_art/10.jpg';
 bg_images[10] = 'images/hidden_art/11.jpg';
 bg_images[11] = 'images/hidden_art/12.jpg';
 bg_images[12] = 'images/hidden_art/13.jpg';
 bg_images[13] = 'images/hidden_art/14.jpg';
 //the delay between change-over, in milliseconds.
 var speed = 10000;
 
 j = bg_images.length;
 function bg_change_over()
	{
    j++;
	if(j < bg_images.length)
	 {
     document.getElementById('left_history').style.backgroundImage = "url('" + bg_images[j] + "')";
	 }
	else
	 {
     j=0;
     document.getElementById('left_history').style.backgroundImage = "url('" + bg_images[j] + "')";
	 }
    setTimeout("bg_change_over()", speed);
	}

 bg_change_over();