if (document.images) {
    continuebuttonup       = new Image();
    continuebuttonup.src   = "welcome/continue.jpg" ;
    continuebuttondown     = new Image() ;
    continuebuttondown.src = "welcome/continue-on.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" );
    }
}