Get the battery checked out...if its almost dead, get the alternator checked out too. If neither try to replace the starter...I had a similar problem with my Caravan...

 

ok from reading other posts iam wondering if it is the main relay or could it be part of the distributer that is failing? the car runs perfectly when it starts

 

SO whenever you try to start it, it turns over with ease right? Or does it just kinda click?

Ive seen where people had their starter just click and it ended up being from an old alarm install where the starter wire was cut and butt connected together poorly.