2 form control drop boxes, i want them to move simultaneously

[LindaD123]

I have 2 drop boxes. They were created with the developer insert, form control and i have them linked to graphs whcih update upon changing the option in a list. i am using a Choose(cell, list name, list name etc....)
Each drop box referneces the same list of items but the results differ as different data is being used for each.
I want to be able to select drop down 1 and have it change drop down 2.
I have searched and searched and cannot figure out how to do this. Can anyone help?

 

[mikerickson]

Link both boxes to the same cell.

 

[Norie]

How should the second dropdown change based on the first?