smenu = new Array( 'sub_1' );

is_DOM = ( document.getElementById ) ? true : false;

function show_menu( m )
{
  hide_menu();

  obj = (is_DOM) ? document.getElementById( m ).style : eval( 'document.' + m );
  obj.visibility = 'visible';
}
		
function hide_menu()
{
  for( i = 0; i < smenu.length; i++ )
  {
    obj = (is_DOM) ? document.getElementById( smenu[ i ] ).style : eval( 'document.' + smenu[ i ] );
    obj.visibility = 'hidden';
  }
}
	
function go( p )
{
  location.href = p;
}