Editor not invoked in child table

Hi everyone..

Given below is the link to my page where I have used parent-child system.
https://e-reporting.in/Data/HTC_Bill/index1.php

When I expand the first column i.e. Bill **of any row, the child table gets populated and new row could be added using Add Bill button. But when click on subsequent rows to expand them, the **Add Bill Button doesn't work as an **empty editor **without any fields do appear.

Please see and help me to get rid of the above.

Thanks & Regards
Shatrughan Sangwan