if (document.images) {
    sydneybuttonup       = new Image();
    sydneybuttonup.src   = "images/A_off.gif" ;
    sydneybuttondown     = new Image() ;
    sydneybuttondown.src = "images/A_ro.gif" ;

    museumbuttonup       = new Image();
    museumbuttonup.src   = "images/B_off.gif" ;
    museumbuttondown     = new Image() ;
    museumbuttondown.src = "images/B_ro.gif" ;
	
	goodbuttonup       = new Image();
    goodbuttonup.src   = "images/good_off.gif" ;
    goodbuttondown     = new Image() ;
    goodbuttondown.src = "images/good_ro.gif" ;

    egyptbuttonup       = new Image();
    egyptbuttonup.src   = "images/D_off.gif" ;
    egyptbuttondown     = new Image() ;
    egyptbuttondown.src = "images/D_ro.gif" ;
	
	yorkbuttonup       = new Image();
    yorkbuttonup.src   = "images/E_off.gif" ;
    yorkbuttondown     = new Image() ;
    yorkbuttondown.src = "images/E_ro.gif" ;

    hbcbuttonup       = new Image();
    hbcbuttonup.src   = "images/F_off.gif" ;
    hbcbuttondown     = new Image() ;
    hbcbuttondown.src = "images/F_ro.gif" ;
	
	nbcnbuttonup       = new Image();
    nbcnbuttonup.src   = "images/G_off.gif" ;
    nbcnbuttondown     = new Image() ;
    nbcnbuttondown.src = "images/G_ro.gif" ;

    sketchbuttonup       = new Image();
    sketchbuttonup.src   = "images/H_off.gif" ;
    sketchbuttondown     = new Image() ;
    sketchbuttondown.src = "images/H_ro.gif" ;
	
	gallerybuttonup       = new Image();
    gallerybuttonup.src   = "images/I_off.gif" ;
    gallerybuttondown     = new Image() ;
    gallerybuttondown.src = "images/I_ro.gif" ;
	
	onebuttonup       = new Image();
    onebuttonup.src   = "images/1_off.gif" ;
    onebuttondown     = new Image() ;
    onebuttondown.src = "images/1_ro.gif" ;
	
	twobuttonup       = new Image();
    twobuttonup.src   = "images/2_off.gif" ;
    twobuttondown     = new Image() ;
    twobuttondown.src = "images/2_ro.gif" ;
	
	threebuttonup       = new Image();
    threebuttonup.src   = "images/3_off.gif" ;
    threebuttondown     = new Image() ;
    threebuttondown.src = "images/3_ro.gif" ;
	
	fourbuttonup       = new Image();
    fourbuttonup.src   = "images/4_off.gif" ;
    fourbuttondown     = new Image() ;
    fourbuttondown.src = "images/4_ro.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" );
    }
}