When I press play it just says error and takes me back to the launcher

Put the summary of the bug you're having here

What I expected to happen was...:
Describe what you thought should happen here
I thought I would just be able to play minecraft happily .
What actually happened was...:
Describe what happened here
What happened was that I turned it on and I couldnt have a nice game of minecraft
Steps to Reproduce:
1. Find a computer that changes screen resolution when you turn minecraft on .

2. ... Turn minecraft on .

3... Change the screen resolution to where it was normally.
4 ... Click play on the minceraft launcher 1.0.7
5... You have your bug .