Merging in tortoiseHg

Question

I am beginner for TortoiseHg.

I create a two branch (default and NewBranch)having different project code commited.

while merging branches and updating merged code, my project is containing only NewBranch code.Why my code is not mix of NewBranch and default codes ?

It seems the Default branch code is replaced by the NewBranch code, instead of merging.

When I am merging the branches, I am getting a message like., "%hg merge --tool:fail--verbose 277"

Also there is no option for merge resolve, which is asking me whether I want to use Mercury resolve or Tool Resolve to solve conflicts.

(Code in the two branches are totally different(seen by hg diff command) then why conflict is not generated?? )

Using a tool resolver I had merge two branches once successfully, but now merge resolver is not even asking me about this selections and doing replacing of code instead of merging.....Why?

I had lost of questions about this.

1. Once I had used mercury conflict resolver, which is not merging 2 branch code, instead replace the code.Why so?

2. Why Merge resolver is not generating Conflict?

3. Why Merge Resolver is not asking me about selection of Resolver tools?

4. Why code is replaced instead of merging?

Also I have seen the videos of https://www.youtube.com/watch?v=sbRxMXVEDc0 and https://www.youtube.com/watch?v=CxtQHcX_MTY but unable to get rid of this trouble.

Please suggest how can I merge code of this 2 branches in my case?