Background problem!

In my game I am using a scrolling background with this code

if (Key.isDown(39))
{
this._x = this._x + 24;
_parent._x = _parent._x - 24;

I want to make a reset/restart button using “Enter” and it worked before… but i realised that once you press it the background has moved so you cant see the menu screen…

Please help! :-/