function preload(){
		 hover1_on= new Image();
     hover1_on.src="images/hover1a.gif";
		 hover1_off= new Image();
     hover1_off.src="images/hover1d.gif";
		 hover2_on= new Image();
     hover2_on.src="images/hover2a.gif";
		 hover2_off= new Image();
     hover2_off.src="images/hover2d.gif";
		 hover3_on= new Image();
     hover3_on.src="images/hover3a.gif";
		 hover3_off= new Image();
     hover3_off.src="images/hover3d.gif";
		 hover4_on= new Image();
     hover4_on.src="images/hover4a.gif";
		 hover4_off= new Image();
     hover4_off.src="images/hover4d.gif";
		 hover5_on= new Image();
     hover5_on.src="images/hover5a.gif";
		 hover5_off= new Image();
     hover5_off.src="images/hover5d.gif";
		 hover6_on= new Image();
     hover6_on.src="images/hover6a.gif";
		 hover6_off= new Image();
     hover6_off.src="images/hover6d.gif";
		 hover7_on= new Image();
     hover7_on.src="images/hover7a.gif";
		 hover7_off= new Image();
     hover7_off.src="images/hover7d.gif";
		 hover8_on= new Image();
     hover8_on.src="images/hover8a.gif";
		 hover8_off= new Image();
     hover8_off.src="images/hover8d.gif";
		 hover9_on= new Image();
     hover9_on.src="images/hover9a.gif";
		 hover9_off= new Image();
     hover9_off.src="images/hover9d.gif";
		 image_off= new Image();
     image_off.src="images/maindefault.gif";  
		 image1= new Image();
     image1.src="images/mainhover1.gif";
     image2= new Image();
     image2.src="images/mainhover2.gif";  
     image3= new Image();
     image3.src="images/mainhover3.gif";   
     image4= new Image();
     image4.src="images/mainhover4.gif";
		 image5= new Image();
     image5.src="images/mainhover5.gif";
		 image6= new Image();
     image6.src="images/mainhover6.gif";
		 image7= new Image();
     image7.src="images/mainhover7.gif";
		 image8= new Image();
     image8.src="images/mainhover8.gif";
		 image9= new Image();
     image9.src="images/mainhover9.gif";  
}   
function roll(imgName1, imgSrc1, imgName2, imgSrc2)
    {
      document[imgName1].src = imgSrc1;
			document[imgName2].src = imgSrc2;
    }
preload();