function toggle_header_image(type,id,image_class) {
  var img = document.getElementById(type+'_header_image');
  var link = document.getElementById(type+'_toggle');
  id = id+1
  if(!header_images[type][id]) {
    id = 0;
  }
	
  img.src = header_images[type][id][0]+'?image_class='+image_class;
  link.href = "javascript:toggle_header_image('"+type+"',"+id+",'"+image_class+"')";
  img.alt = header_images[type][id][1]; 
  img.title = header_images[type][id][1]; 
}
var header_images = new Array();