if (document.images) 
{
      img1 = new Image();
      img2 = new Image();
      img3 = new Image();
	  img4 = new Image();
      img1.src ="images/babies_over.jpg";
      img2.src ="images/families_over.jpg";
      img3.src ="images/graduations_over.jpg";
	  img4.src ="images/formals_over.jpg";
}