function MoveLeft()
{
    new Effect.MoveBy('bigbox', 0, 780 , 
                              {
                                  duration: 0.4,  
                                  transition: Effect.Transitions.sinoidal,
                                  queue: 'end'
                              });
}

function MoveRight()
{
    new Effect.MoveBy('bigbox', 0, -780 , 
                              {
                                  duration: 0.4,  
                                  transition: Effect.Transitions.sinoidal,
                                  queue: 'end'
                              });
}