function fnPreloadImages(the_images_array) {
  for (loop = 0; loop < the_images_array.length; loop++) {
    var an_image = new Image();
	an_image.src = "images/" + the_images_array[loop]
  }
}

function fnImageArray() {
  var the_images = new Array('btn_mission_over.gif', 'btn_staff_over.gif', 'btn_facilities_over.gif', 'btn_highlander_over.gif', 'btn_links_over.gif', 'btn_summercamps_over.gif', 'btn_news_over.gif');
  fnPreloadImages(the_images);
}

function fnMouseOver(btn) {
	btn.src = "images/btn_" + btn.name + "_over.gif";
}

function fnMouseOut(btn) {
	btn.src = "images/btn_" + btn.name + ".gif";
}