function showSubBar(new_sub)
{
	last_layer=eval(doc+last_sub+sty)
	new_layer=eval(doc+new_sub+sty)
	last_layer.visibility='hidden'
	new_layer.visibility='visible'
	last_sub=new_sub
}

function chng(picName,pic)
{
document[picName].src=pic
}