function showID(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 hideID(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' 
}