function switchlayer(Layer_Name) {
        var GECKO = document.getElementById? 1:0 ;
        var NS = document.layers? 1:0 ;
        var IE = document.all? 1:0 ;
      
        if (GECKO) {
           var display_test = document.getElementById(Layer_Name).style.display;
          
           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.display=(document.all[Layer_Name].style.display==
          'block') ? 'none' : 'block';}         
}