car won't start

My 97 es300 won't start. When I try to start it, it just clicks at me real fast and while it's clicking all of the inside lights flicker. Sometimes nothing happens when I try to start it. The headlights still work so I don't think it's the battery. Any ideas?

Check that all of the connections between the battery and starter are clean and tight and the battery is good.Will it start with a jump?