c0off = new Image(); c0off.src = "images/menu1.jpg"; 
c0on = new Image(); c0on.src = "images/menu11.jpg"; 

c1off = new Image(); c1off.src = "images/menu2.jpg"; 
c1on = new Image(); c1on.src = "images/menu22.jpg"; 

c2off = new Image(); c2off.src = "images/menu3.jpg"; 
c2on = new Image(); c2on.src = "images/menu33.jpg";
 
c3off = new Image(); c3off.src = "images/menu4.jpg"; 
c3on = new Image(); c3on.src = "images/menu44.jpg"; 

c4off = new Image(); c4off.src = "images/menu5.jpg"; 
c4on = new Image(); c4on.src = "images/menu55.jpg"; 
function img_act(imgName) 
{ 
imgOn = eval(imgName+"on.src"); 
document.images[imgName].src = imgOn; 
} 

function img_inact(imgName) 
{ 
imgOff = eval(imgName+"off.src");
document.images[imgName].src = imgOff; 
}