var img_return = 0;
 
var arImages=new Array();
function az_preload() {
 for(x=0; x < img_preload.length; x++) {
  arImages[x]=new Image();
  arImages[x].src=img_preload[x];
 }
}

function az_swap_over(N) {
var i;
  for (i=0; i < img_names.length; i++) {
   var img_name = 'th_'+ i;
   if (i == N)  document[img_name].src = img_folder + img_names[i] + ext_th_over; 
   else document[img_name].src = img_folder + img_names[i] + ext_thumb;
      }  
 }

 function az_swap_main(N) {
    document.main.src = img_folder + pre_main + img_names[N] + ext_main;
   img_return = N;
 }
 
 function az_restore() {
   xxx = az_swap_over(img_return);

 }
    ///   Building the row of thumbnails with code
var i;
thumbs = '<div class="picture_box">';
  for (i=0; i < img_names.length; i++) {
    thumbs = thumbs + '<img src="' + img_folder + img_names[i] + ext_thumb + '" alt="' + img_alt[i] + '" name="th_'+i+'" onMouseOver="az_swap_over('+i+')" onClick="az_swap_main('+i+')" onMouseOut="az_restore()">';
     }
 thumbs = thumbs + '<\/div>'; 
     ///    alert(thumbs); 
      ///end building thumb row