Using a path from a user in the install directory

[jtbjustin]

Hello,
Im trying to make a install file using the Modern User Interface. What im trying to do is make a installer to update some files that are already on a computer. What I would like to be able to do is get the directory of the installed files from the user, store that in a variable and then in my script add more to that path, and then finally install into that directory. Now I know what I just said made pretty much no sense so let me give an example, say you have previously installed my program, lets call it TestP, and this program is installed in C:\Program Files\TestP on your computer but the directory that I want to install the new files is actually C:\Program Files\TestP\NewFiles what I want to do is ask the user where the root directory for TestP is on their computer (Ex. C:\Program Files\TestP) but then actually install my new files into C:\Program Files\TestP\NewFiles
Im not trying to find the parent directory of C:\Program Files\TestP\NewFiles (like the script listed in Appendix C although it may be a start in the right direction, im not sure), im trying to have the user tell me where C:\Program Files\TestP is located on their computer because when the user originally installed TestP they may have installed it in a different location than the default.
What I have been trying to do is re-dfine the variable that is assigned on the directory page to install.
EX.
!define MUI_DIRECTORYPAGE_VARIABLE $NewV
!insertmacro MUI_PAGE_DIRECTORY

I just do not know what to do next. And also with my current script making this change results in a compile error, I have attached an example of my script.

Any help is greatly appreciated.

-Justin B.

[dienjd]

Is there any way you can detect the previously installed location (through the registry maybe)? This would be a better user experience than having users manually enter this, and there's always the chance of them entering an incorrect path.

[jtbjustin]

good point.

I have solved my problem, thank you for your help!