if (document.images) {

    enterup       = new Image();
    enterup.src   = "images/menu/enter_up.gif" ;
    enterdown     = new Image() ;
    enterdown.src = "images/menu/enter_over.gif" ;

    playup       = new Image();
    playup.src   = "images/menu/play_up.gif" ;
    playdown     = new Image() ;
    playdown.src = "images/menu/play_over.gif" ;

    workup       = new Image();
    workup.src   = "images/menu/work_up.gif" ;
    workdown     = new Image() ;
    workdown.src = "images/menu/work_over.gif" ;

    belongup       = new Image();
    belongup.src   = "images/menu/belong_up.gif" ;
    belongdown     = new Image() ;
    belongdown.src = "images/menu/belong_over.gif" ;

    promoteup       = new Image();
    promoteup.src   = "images/menu/promote_up.gif" ;
    promotedown     = new Image() ;
    promotedown.src = "images/menu/promote_over.gif" ;

    connectup       = new Image();
    connectup.src   = "images/menu/connect_up.gif" ;
    connectdown     = new Image() ;
    connectdown.src = "images/menu/connect_over.gif" ;

}

function buttondown( buttonname )
{
    if (document.images) {
      document[ buttonname ].src = eval( buttonname + "down.src" );
    }
}
function buttonup ( buttonname )
{
    if (document.images) {
      document[ buttonname ].src = eval( buttonname + "up.src" );
    }
}