if (document.images) {
    rockbuttonout       = new Image();
    rockbuttonout.src   = "/images/rock.gif" ;
    rockbuttonover     = new Image() ;
    rockbuttonover.src = "/images/rock_over.gif" ;
    popbuttonout       = new Image();
    popbuttonout.src   = "/images/pop.gif" ;
    popbuttonover     = new Image() ;
    popbuttonover.src = "/images/pop_over.gif" ;
    traditionalbuttonout       = new Image();
    traditionalbuttonout.src   = "/images/traditional.gif" ;
    traditionalbuttonover     = new Image() ;
    traditionalbuttonover.src = "/images/traditional_over.gif" ;
    countrybuttonout       = new Image();
    countrybuttonout.src   = "/images/country.gif" ;
    countrybuttonover     = new Image() ;
    countrybuttonover.src = "/images/country_over.gif" ;


}
function buttonout( buttonname )
{
    if (document.images) {
      document[ buttonname ].src = eval( buttonname + "out.src" );
    }
}
function buttonover ( buttonname )
{
    if (document.images) {
      document[ buttonname ].src = eval( buttonname + "over.src" );
    }
}