if (document.images) {


	img20on = new Image();           
	img20on.src = "images/subbtn_overview_b.gif";  
	img21on = new Image();           
	img21on.src = "images/subbtn_helixmailer_b.gif";  
	img22on = new Image();           
	img22on.src = "images/subbtn_reseller_b.gif";  


	img20off = new Image();          
	img20off.src = "images/subbtn_overview_a.gif"; 
	img21off = new Image();          
	img21off.src = "images/subbtn_helixmailer_a.gif"; 
	img22off = new Image();          
	img22off.src = "images/subbtn_reseller_a.gif"; 

}