P-trap Replacement - leak

Long-story short... Took apart P-trap to clean out drain in kids' bathroom and accidentally broke "collar" (if that's proper term) that join one part of P-trap (ABS) to the other. It's a 1 1/2" trap.

Bought another ABS, 1 1/2" trap to harvest the "U" part and tie into the other part (which is attached to part that goes into wall). There is a leak at the collar where I've joined them.

Any advice? I would have thought I could marry one part of ABS p-trap to another without much trouble.

Thank you.

Problem solved, but interesting discovery (at least for me)... one part of one company's 1 1/2" ABS p-trap will not necessarily fit with another company's... Had to cut out the other part of the p-trap and glue all new back to the other ABS pipe... not too hard, but more effort than I expected.

The only things standard are the ends...what they do in the middle is up to the individual company that makes them.