Rearrange list item

hi,
I'm trying to create a form list that enable a user to choose his/her preferred method of contact. For example, I have a form with items such as:
1. Mobile
2. Email
3. SMS

And if the user clicks on SMS, the menu will become:
1. Mobile
2. SMS
3. Email

So whenever the user clicks on an item, it just shift upwards.

I've seen this before but I've no idea how to do this.
Any help is greatly appreciated. Thanks.