What project manager should do to resolve conflict between to team members?

Project manager need to ensure good relationship between team members and need to provide them the opportunity to respect each other. Also external event like parties, cinema may help in this direction.

When you talk with any member show respect to him and to the other members also.

Follow one of the methods
1) Competition : when one shows his/her authority to fix the conflict.this is required when the conflict needs to be resolved as the projecct is in critical phase. win-loose approach.

2) collaboration : in this the two parties sit togather and a solution is decided with the both party happy about the resolution. It is time consuming but is good to do when the satkes are high and the confict is affecting the efficiency. win - win approach
3) Avoidance : if the issue is not worth putting time into and will not affect the productivity in long run generally the issue is avoided. Loose -loose approach.

4)Accomodating : this is the flip side of the competition approach. where u let the other party have their way. loose -win approach.