function showLayer( layerName ) {
   changeProperty( layerName, "visibility", "visible" );
}

function hideLayer( layerName ) {
   changeProperty( layerName, "visibility", "hidden" );
}

function changeProperty( layerName, layerProperty, layerValue ) {
   if ( isNaN( layerValue ) ) {
      layerValue = "'" + layerValue + "'";
   }
   if (document.all ) {
      if ( document.all[ layerName ] != null) {
         if ( document.all[ layerName ][ layerProperty ] != null ) {
            eval( "document.all[ '" + layerName + "' ]." + layerProperty + " = " + layerValue );
         }
         else if ( document.all[ layerName ].style != null ) {
            if ( document.all[ layerName ].style[ layerProperty ] != null ) {
               eval( "document.all[ '" + layerName + "' ].style[ '" + layerProperty + "' ] = " + layerValue );
            }
         }
      }
   } else if (document.layers) {
      eval( "document.layers[ '" + thisLayerName + "' ]." + layerProperty + " = " + layerValue );
   } else if (document.getElementById) {
      if ( document.getElementById( layerName ) != null ) {
         if ( document.getElementById( layerName ).style != null ) {
            if ( document.getElementById( layerName ).style[ layerProperty ] != null ) {
               eval( "document.getElementById( '" + layerName + "' ).style." + layerProperty + " = " + layerValue );
            } else if ( document.getElementById( layerName )[ layerProperty ] != null ) {
               eval( "document.getElementById( '" + layerName + "' )." + layerProperty + " = " + layerValue );
            }
         }
      }
   }
}

function getProperty( layerName, layerProperty ) {
   if (document.all ) {
      if ( document.all[ layerName ] != null) {
         if ( document.all[ layerName ][ layerProperty ] != null ) {
            return eval( "document.all[ '" + layerName + "' ]." + layerProperty );
         }
         else if ( document.all[ layerName ].style[ layerProperty ] != null ) {
            if ( document.all[ layerName ].style[ layerProperty ] != null ) {
               return eval( "document.all[ '" + layerName + "' ].style[ '" + layerProperty + "' ]" );
            }
         }
      }
   } else if (document.layers) {
      return eval( "document.layers[ '" + thisLayerName + "' ]." + layerProperty );
   } else if (document.getElementById) {
      if ( document.getElementById( layerName ) != null ) {
         if ( document.getElementById( layerName ).style != null ) {
            if ( document.getElementById( layerName ).style[ layerProperty ] != null ) {
               return eval( "document.getElementById( '" + layerName + "' ).style." + layerProperty );
            } else if ( document.getElementById( layerName )[ layerProperty ] != null ) {
               return eval( "document.getElementById( '" + layerName + "' )." + layerProperty );
            }
         }
      }
   }
}

function changeImage( name, image ) {
   if ( document.images[ name ] ) {
      document.images[ name ].src = image;
   }
}

function swapImage( name, image ) {
   document.images[ name ].src = image;
}

function sizeIFrame( name, width, height ) {
   changeProperty( name, "height", height );
   changeProperty( name, "width", width );
}