uninstall function

I have two functions that do the same one for the install and one for the uninstall
I want to unify them under the same function (save duplicate code)
how do i do it - the compiler tells me that any call to a function during the uninstall the function name must start with un. ?

I do this:

!macro DualUseFunctions_ un_



function ${un_}StartServices

# ...

functionEnd



function ${un_}SetPathVar

# ...

  ${${un_}WordFind} "$R0" "_" "E$0" $1

# ...

  ${${un_}WordAdd} "$R0" ";" "-$0" $R0

functionEnd



!macroend



!insertmacro DualUseFunctions_ ""

!insertmacro DualUseFunctions_ "un."

Thanks