if (document.images) {
    z2up       = new Image();
    z2up.src   = "/skin/frontend/default/durasight2010/images/z2_alloy_logo.gif" ;
    z2down     = new Image() ;
    z2down.src = "/skin/frontend/default/durasight2010/images/z2_alloy_logo_roll.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" );
    }
}