if (document.images) {
nav1_on =new Image();  nav1_on.src ="/images/nav01_on.gif"; 
nav1_off=new Image();  nav1_off.src="/images/nav01_off.gif"; 

nav2_on =new Image();  nav2_on.src ="/images/nav02_on.gif"; 
nav2_off=new Image();  nav2_off.src="/images/nav02_off.gif"; 

nav3_on =new Image();  nav3_on.src ="/images/nav03_on.gif"; 
nav3_off=new Image();  nav3_off.src="/images/nav03_off.gif"; 

nav4_on =new Image();  nav4_on.src ="/images/nav04_on.gif"; 
nav4_off=new Image();  nav4_off.src="/images/nav04_off.gif"; 

nav5_on =new Image();  nav5_on.src ="/images/nav05_on.gif"; 
nav5_off=new Image();  nav5_off.src="/images/nav05_off.gif"; 

nav6_on =new Image();  nav6_on.src ="/images/nav06_on.gif"; 
nav6_off=new Image();  nav6_off.src="/images/nav06_off.gif"; 

}

function imgOn(i) {
	if (document.images) 
		eval('document.nav'+i+'.src = nav'+i+'_on.src');
}

function imgOff(i) {
	if (document.images) 
		eval('document.nav'+i+'.src = nav'+i+'_off.src');
}