Open Question: My acer wont charge. Help me thanks!!!!?

Hello, I have an acer Aspire 5570z that will not charge. The first cord broke. I Got a new one a week ago that does not fit fully in the slot but was working fine until 2 or 3 days ago. Now. when my laptop is on my lap. It wont charge. but when its not. It will charge.. But the second I move it, it will stop. how do I fix this so i can use it again? Thanks