Please disregard previous

I have a form where I have scattered a record object to name oClaimant and passed that object to this form.
How do I set the control source to this property? No matter what I do, it errors out or doesn't display the contents of the property.

    WITH this.oParent
	.txtFirstName.ControlSource = this.oClaimant.first_name
    ENDWITH

Thanks in advance.