As stated above it is recommended you look at the TweenPosition API which can be found here. If you don’t feel like it then all you need to know is change the last parameter in the TweenPosition to a lower number, so something like this.
Check out the API. It basically means you can overwrite the tween when it’s currently going, so if you want to stop it but it’s somehow still doing the first tween it will stop the first tween.