Grouping Multiple Columns

I am trying to display five columns from three seperate tables. I thought the GROUP BY operator would fix this, but I have more than one column to select. The query is fine but I have redundant fields showing. Oh, I'm not worried about the calculation "[employee.salary]*0.1 AS Salary_After_Raise." I just want to concentrate on narrowing the fields down first.

SELECT ID, FirstName, LastName, Salary, [employee.salary]*0.1 AS Salary_After_Raise, City
FROM worksat INNER JOIN store ON worksat.store = store.storenumber, employee
WHERE worksat.store = store.storenumber
GROUP BY city, id, firstname, lastname, salary
ORDER BY city;