if (document.all) {
      layerview='document.all.'
      styleview='.style.'
  }else if (document.layers) {
      layerview='document.layers.'
      styleview='.'
  } 

 function show(Layer){
   var Layer;
    eval(layerview+Layer+styleview+'visibility="visible"') 
    eval(layerview+Layer+styleview+'display=""') 
}

 function hide(Layer){
   var Layer; 
    eval(layerview+Layer+styleview+'visibility="hidden"') 
    eval(layerview+Layer+styleview+'display="none"') 
}