if (document.layers) { 
		layerRef=".layers[";
		styleRef="]";
	}
	else if (document.all) { 
		layerRef=".all[";
		styleRef="].style";
	}
	else if (document.getElementById) { 
		layerRef=".getElementById(";
		styleRef=").style";
	}

	function sluitfoto(){
		eval ("document"+layerRef+"'topfoto1'"+styleRef+".display='none'");
		eval ("document"+layerRef+"'topfoto2'"+styleRef+".display='none'");
		eval ("document"+layerRef+"'topfoto3'"+styleRef+".display='none'");
	}	
	
	function toonfoto1(){
		eval ("document"+layerRef+"'topfoto1'"+styleRef+".display='block'");
	}	
	function toonfoto2(){
		eval ("document"+layerRef+"'topfoto2'"+styleRef+".display='block'");
	}	
	function toonfoto3(){
		eval ("document"+layerRef+"'topfoto3'"+styleRef+".display='block'");
	}