if (document.images) {
    contactButtonup       = new Image();
    contactButtonup.src   = "images/contactButton.jpg" ;
    contactButtondown     = new Image() ;
    contactButtondown.src = "images/contactButtonRollover.jpg" ;
}
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" );
    }
}