Car won't tick over or start!?

Hi, I have a 95 fto import and it won't start. It's been sitting in my drive for a few weeks and the last time I started it, it was fine. Today I tried to start it and it won't tick over there are no dash lights coming on or anything. The only light that is on is the door open light. I thought it was the battery so I connected it up to my focus for about 20 mins and still nothing. I put my focus battery in and again nothing. Can anyone help me??