Changing a control in a subform

[velcrowe]

I have a subform on my main order form. I would like to click a button on my main order form and have it change a control on the subform. For instance, I have 2 controls on my subform, control 1 is a text field, and control 2 is a yes/no box.

When i click the button on my main for order form, I would like it to evaluate control 1 on my subform so that it can adjust control 2.

I would like to see if control 1 is null then set control 2 to yes or true. Thank you in advance for all your help.

 

[RuralGuy]

See if this link helps a bit.

 

[velcrowe]

I am trying update all the records. I am trying to update a yes/no field based on null values in my other text fields. If field A, field B, and field C are null for all records, I would like the accompanying yes/no box to be checked yes for signifying their null values.