There have been some good comments posted here that I would recommend reading them - especially the one by cgmv123.
For those who are looking for more of a tutorial of one way of accomplishing this task - currently up while button 1 and not top limit switch else down while button 2 and not bottom limit switch -
Please refer to this tutorial that I have made,
Click here for tutorial It is under limit switch tutorial, although the state machine tutorial is a similar scenario.