Fill in form text box based on selection from a combobox

[Kemidan2014]

I have seen alot of VBA ways to do this but surely there is a way to achieve what i want since the values i am working with all come from the same table?
i have a table called "Thelists" In this table i have fields named whymake, Whyship, 3PWM, 3PWS
I have a form called "openComplaintsform"
in opencomplaintsform i already have it set up to have combo box to select Whymake and combobox to select Whyship

1) When the user picks an option in WhyMake field in the form i would like text box 3PWM to fill in the associated value i populated form Thelists table? Can this be done using a simple SQL type statement in default value property of the text box? or some other property? or is VBA absolutely required for this?
1) i recently added the 2 fields 3PWM and 3PWS to the form as text box, Can they remain as text box or do they need to changed to combobox?

 

[Micron]

Something seems not right there. Methinks it's because the table is not properly normalized, otherwise all fields related to the form are right there and all you'd need to do is bind them to the proper controls. If that is the case and you're not prepared to fix it, then perhaps set the textbox controlsource properties to refer to the combo field list. Perhaps like
=forms!myFormName.myComboName.Column(x) where x is the column position of the combo list. The list count is zero based.
Post a pic of your table design (or better, your relationships, if you have created them) if you want your design checked.