// JavaScript Document
 var state = 'none';

    function showhidemenu(layer_ref) {

      if (state == 'block') {
        state = 'none';
      }
      else {
        state = 'block';
      }
      if (document.all) { //IS IE 4 or 5 (or 6 beta)
        eval( "document.all." + layer_ref + ".style.display = state");
      }
      if (document.layers) { //IS NETSCAPE 4 or below
        document.layers[layer_ref].display = state;
      }
      if (document.getElementById &&!document.all) {
        
        hza = document.getElementById(layer_ref);
        hza.style.display = state;
      }
    }