How to insert a new row from the form for the child grid in the child tabpage.

I have created a new grid in tabPage1 for ParentTable and child grid for childTable in tabPage2. After opening the form the data is getting displayed successfully but when i am in the tabpage2 and click on ctrl + N the new row is inserting a new row in the parent grid and not in the child grid. How to insert a new row from the form for the child grid in the child tabpage.

Thanks

N