This should work if you manually re-execute the cell with the import statement.
If you want to automatically re-run the script, you could do the following:
a. for re-running when a variable changes in the notebook, but the include statement in a block with this variable, e.g.
begin x include("myscript.jl") end
b. for re-running if the script itself changes, use Revise:
using Revise includet("myscript.jl")