function showLAYER(idName){ 
  if ( document.getElementById)  document.getElementById( idName ).style.visibility   = 'visible' 
  else if ( document.all ) document.all( idName ).style.visibility = 'visible' 
  else if ( document.layers ) document.layers[ idName ].visibility = 'show' 
}
function hideLAYER(idName){ 
  if ( document.getElementById )
              document.getElementById( idName ).style.visibility   = 'hidden' 
  else if ( document.all ) document.all( idName ).style.visibility = 'hidden' 
  else if ( document.layers ) document.layers[ idName ].visibility = 'hide' 
}