Is there a method to merge two programmatic guis to form one m file for both?

Is there any method to merge two programmatic guis to make one .m file and one of them will be the main gui where the other will be the sub gui

when executing the m file will show the main gui then after pressing a button will call for the second

[Zine]

The two guis are in different m files and working fine separately and I want to put them in only one file

Answer 1

[Zine]

I tried a way and till now it is working, by copying the code of the sub gui to the m file of the main gui but outside of its limit (ie after the end of the first code) and remove any statement that initialize the data or handles from the second code, to call the second gui just write the name of its function in callback