it has to be imported into each activity you want to use it in.
you can create a code module, a class or a library. you save
these modules in your shared code folder or, in the case of
a library, in your additional libraries folder.
you simply bring them into your apps like you you would any
3rd party code. because your function is not part of b4a's base code,
you cannot simply call it and expect it to be recognized by the compiler.
you import it and then you can reference it just as you would any
other "function". everybody has a tool kit of routines that are used
over and over.