ns4 = (document.layers)? true:false
	ie4 = (document.all)? true:false
	ns6 = (document.getElementById)? true:false

	function init()
	
		{
		
		if (ns4) block = document.layers["Layer1"]
		if (ie4) block = Layer1.style
		if (ns6) block = document.getElementById("Layer1").style
		
		}
		
	function swap(layer_visibility)
	
		{
		block.visibility = (layer_visibility);
		}