Multilievel Nested GridView Variable width issue in ASP.Net

Hello. I have this interface of multilevel grid built in VStudio 2010 using asp.net.

My grid will show the 2nd level then the 3rd (2nd grid as its parent) when plus signs are clicked. however the parent gridview loses its original width when the panel shows up. 

Is there a way to maintain its width so the design will be as is.

please see the picture by clicking the link

Attached image

Any help would be appreciated!

Thanks and God bless!

Bob