l_opera = navigator.userAgent.toLowerCase().indexOf('opera') != -1;

  function layer_hide(p_layer){
    var l_layer = document.getElementById(p_layer);
    if (document.layers){
      l_layer.visibility = 'hide';}
    else{
      l_layer.style.visibility = 'hidden';} 
  }

  function layer_show(p_layer){
    var l_layer = document.getElementById(p_layer);
    if (document.layers){
      l_layer.visibility = 'show';}
    else{
      l_layer.style.visibility = 'visible';} 
  }
  
  function layer_set_x(p_layer, p_x){
    var l_layer = document.getElementById(p_layer);
    if (document.layers)
      l_layer.left = p_x;
    else if (l_opera)
      l_layer.style.pixelLeft = p_x;
    else
      l_layer.style.left = p_x+"px";
  }

  function layer_set_y(p_layer, p_y){
    var l_layer = document.getElementById(p_layer);
    if (document.layers)
      l_layer.top = p_y;
    else if (l_opera)
      l_layer.style.pixelTop = p_y;
    else
      l_layer.style.top = p_y+"px";
  }

  function layer_is_visible(p_layer){
    var l_layer = document.getElementById(p_layer);
    if (document.layers){
      if (l_layer.visibility == 'show')
        return true;
      else
        return false;
    }
    else{
      if (l_layer.style.visibility == 'visible')
        return true;
      else
        return false;
    }
  }