Referencing a field in a Tab Control Sub Form

[Muzicmn]

I have a form, within this form i am using a Tab Control to allow me to have several subforms within that main form. Works great except when i try to reference a control within one of those sub forms

Main form: frmStudentInfo
subform on a Tab Control: subfrmParentInfo


what i am trying to do is when the address on frmStudentInfo is updated then the address_id in subfrmParentInfo = address_id in frmStudentInfo

Its prob something simple but i cant figure it out

thanks for the help

Ricky