if (document.images) 
{  
img01on = new Image;
img01off = new Image; 

img02on = new Image;
img02off = new Image; 

img03on = new Image;
img03off = new Image; 

img04on = new Image;
img04off = new Image; 

img05on = new Image;
img05off = new Image; 

img01on.src = "images/but001.gif";
img01off.src = "images/but001o.gif"; 

img02on.src = "images/but002.gif";
img02off.src = "images/but002o.gif"; 

img03on.src = "images/but003.gif";
img03off.src = "images/but003o.gif"; 

img04on.src = "images/but004.gif";
img04off.src = "images/but004o.gif"; 

img05on.src = "images/but005.gif";
img05off.src = "images/but005o.gif"; 
}
function imgOutt(imgName) { 
	if (document.images) { 
	imgOn = eval(imgName + "on.src");
	document[imgName].src = imgOn
	} 
} 
function imgOverr(imgName) { 
	if (document.images) { 
	imgOff = eval(imgName + "off.src");
	document[imgName].src = imgOff
} 
}