if (document.images) {
bordersoff = new Image
bnoff = new Image
amazonoff = new Image
iboff = new Image

borderson = new Image
bnon = new Image
amazonon = new Image
ibon = new Image

bordersoff.src = "images/nav_borders.gif"
bnoff.src = "images/nav_bn.gif"
amazonoff.src = "images/nav_amazon.gif"
iboff.src = "images/nav_ib.gif"

borderson.src = "images/nav_borders_r.gif"
bnon.src = "images/nav_bn_r.gif"
amazonon.src = "images/nav_amazon_r.gif"
ibon.src = "images/nav_ib_r.gif"

}
else {

bordersoff =  " "
bnoff =  " "
amazonoff =  " "
iboff =  " "

borderson =  " "
bnon =  " "
amazonon =  " "
ibon =  " "

document.borders =  " "
document.bn =  " "
document.amazon =  " "
document.ib =  " "

}