if(document.images){
	pic1= new Image(48,48); pic1.src="images/circle1_roll.jpg"; 
	pic2= new Image(48,48); pic2.src="images/circle2_roll.jpg"; 
	pic3= new Image(48,48); pic3.src="images/circle3_roll.jpg"; 
  	pic4= new Image(48,48); pic4.src="images/circle4_roll.jpg"; 
	pic5= new Image(48,48); pic5.src="images/circle5_roll.jpg"; 
	pic6= new Image(48,48); pic6.src="images/circle6_roll.jpg"; 
}