function backward(){
if (which>0){
which--
document.images.photoslider.src=photos[which];
idDescription.innerHTML = descriptions[which];
document.rotater.B1.src="images/back.gif";
document.rotater.B2.src="images/next.gif";
}
if (which==0)
{
document.rotater.catalogNavigator.B1.src="images/back_disabled.gif"
document.rotater.catalogNavigator.B2.src="images/next.gif"
}
}

function forward(){
if (which<photos.length-1){
which++
document.images.photoslider.src=photos[which];
idDescription.innerHTML = descriptions[which];
document.rotater.catalogNavigator.B1.src="images/back.gif";
document.rotater.catalogNavigator.B2.src="images/next.gif";
}
if (which==photos.length-1)
{
	
document.rotater.catalogNavigator.B1.src="images/back.gif"
document.rotater.catalogNavigator.B2.src="images/next_disabled.gif"
}
}