function slide_menu(menu_name){
  $("#" + menu_name).slideDown("slow");
}
function hide_menu(menu_name){
  $("#" + menu_name).hide();
}
function switch_pics(image_id, new_image){
//console.log($("#" + image_id).src);
  expression = "delayed_fadein('" + image_id + "','" + new_image + "')";
  $("#" + image_id).fadeOut('fast', function(){delayed_fadein(image_id,new_image)});
}
function delayed_fadein(image_id,new_image){
  $("#" + image_id).attr('src',new_image);
  $("#" + image_id).fadeIn('slow');
}