function switchlayer(Layer_Name)
{
var GECKO = document.getElementById? 1:0 ;
var NS = document.layers? 1:0 ;
var IE = document.all? 1:0 ;

if (GECKO)
{
document.getElementById(Layer_Name).style.display=
(document.getElementById(Layer_Name).style.display=='block') ? 'none' : 'block';
}
else if (NS)
{
document.layers[Layer_Name].display=
(document.layers[Layer_Name].display=='block') ? 'none' : 'block';
}
else if (IE)
{
document.all[Layer_Name].style.visibility=
(document.all[Layer_Name].style.visibility=='visible') ? 'hidden' : 'visible';
}
}