if (document.images) {


	img40on = new Image();           
	img40on.src = "images/subbtn_overview_b.gif";  
	img41on = new Image();           
	img41on.src = "images/subbtn_programming_b.gif";  
	img42on = new Image();           
	img42on.src = "images/subbtn_ecommerce_b.gif"; 
	img43on = new Image();           
	img43on.src = "images/subbtn_design_b.gif"; 


	img40off = new Image();          
	img40off.src = "images/subbtn_overview_a.gif"; 
	img41off = new Image();          
	img41off.src = "images/subbtn_programming_a.gif"; 
	img42off = new Image();          
	img42off.src = "images/subbtn_ecommerce_a.gif"; 
	img43off = new Image();          
	img43off.src = "images/subbtn_design_a.gif"; 

}