if (document.images)
{
buttonoff = new Image(); 
buttonoff.src = "images/homebutton.gif"; 
buttonon = new Image(); 
buttonon.src = "images/homebuttonon.gif";
button1off = new Image(); 
button1off.src = "images/aboutbutton.gif"; 
button1on = new Image(); 
button1on.src = "images/aboutbuttonon.gif";
button2off = new Image(); 
button2off.src = "images/whatbutton.gif"; 
button2on = new Image(); 
button2on.src = "images/whatbuttonon.gif";
button3off = new Image(); 
button3off.src = "images/foliobutton.gif"; 
button3on = new Image(); 
button3on.src = "images/foliobuttonon.gif";
button4off = new Image(); 
button4off.src = "images/contactbutton.gif"; 
button4on = new Image(); 
button4on.src = "images/contactbuttonon.gif";
}
function On(imageName)
{if (document.images)
{document[imageName].src = eval(imageName+"on.src");}
}
function Off(imageName)
{if (document.images)
{document[imageName].src = eval(imageName+"off.src");}
}