Try this
If @NewStatus = 'InOffice'
BEGIN
Update tblEmployee set InOffice = -1 where EmpID = @EmpID
END
Else If @NewStatus = 'OutOffice'
BEGIN
Update tblEmployee set InOffice = -1 where EmpID = @EmpID
END
Else If @NewStatus = 'Home'
BEGIN
Update tblEmployee set Home = -1 where EmpID = @EmpID
END