function preload() {
  var az = new Image();
  az.src = "images/home_h.jpg";
  var bz = new Image();
  bz.src = "images/acception_h.jpg";
  var cz = new Image();
  cz.src = "imagescontacts_h.jpg";
  var dz = new Image();
  dz.src = "images/designer_h.jpg";
  var ez = new Image();
  ez.src = "images/about_h.jpg";
  var fz = new Image();
  fz.src = "images/gallery_h.jpg";
  var jz = new Image();
  jz.src = "images/materials_h.jpg";
  var hz = new Image();
  hz.src = "images/schedule_h.jpg";
  var iz = new Image();
  iz.src = "images/forum_h.jpg";
  var jz = new Image();
  jz.src = "images/mail_h.jpg";
}