var activelayer = 0;
    ns4   = (document.layers) ? true:false;                 // netscape 4
    ie   = (document.all) ? true:false;                    // ie4+    
    others = ((document.getElementById)&&(!ie))?true:false;   // others.

    function getTheElementObject(element) {
      //alert("inne i get"+element)
      var elementObj;
      if(ns4) {
        elementObj = document.layers[element];
      } else if(ie) {
        //alert("inne i if "+element)
        elementObj = document.all(element);
      } else if(others) {
        elementObj = document.getElementById(element);
      }
      //alert("inne i get "+elementObj)
      return elementObj;
    }


    function getTheElementObjectStyle(element) {
      //alert("inne i get"+element)
      var elementStyle;
      if(ns4) {
        elementStyle = document.layers[element];
      } else if(ie) {
        //alert("inne i if "+element)
        elementStyle = document.all(element).style;
      } else if(others) {
        elementStyle = document.getElementById(element).style;
      }
      //alert("inne i get "+elementStyle)
      return elementStyle;
    }
    
  function showLayer(layerName) {
    //alert("inne i showLayer"+layerName);
    activelayer = layerName;
    getTheElementObjectStyle(layerName).display = "block";
  }
  
  function hideLayer(layerName){
    getTheElementObjectStyle(layerName).display = "none";
    activelayer = null;
  }