//	レイヤの表示切替
function LayerOnOff(onlayer,offlayer){
	//	IE5/NN6
	if(document.getElementById){
		document.getElementById(onlayer).style.visibility		= 'visible' ;
		document.getElementById(offlayer).style.visibility	= 'hidden' ;
	}else
	//	IE4(未確認)
	if(document.all){
		document.all(onlayer).style.visibility	= 'visible' ;
		document.all(offlayer).style.visibility	= 'hidden' ;
	}else
	//	NN4
	if(document.layers){
		document.layers[onlayer].visibility		= 'visible' ;
		document.layers[offlayer].visibility	= 'hidden' ;
	}
}