Switch order of fields on slip entry

Hello! 

I would just like to know if it's possible to switch the order of the fields in the slip entry window. I want to put the client field before the task. I've tried to do this by clicking preferences in the slip entry window and clicking slip entry on the left side menu under "Slips". I move client above activity and press okay but the fields are still the same. Maybe I am not understanding this correctly and doing something wrong. I would appreciate any help to fix this issue. Thank you!