Huskee Riding Mower won't start?

I have a Huskee riding mower and it will not start. When I turn the key I hear a clicking noise near the battery. I sounds like it's coming from the solenoid, but I have replaced the solenoid and the clicking noise is still there. The battery on the mower is about a month old. What else could it be? When I removed the battery to replace the solenoid it was on it's side for a minute, could that be the problem?