Query by Main form and give the result as input to a combo box sub

[Manohar]

Hi,
We are using nest sub forms for entering data. With the three child fields
linked to parent fields.
We have three subforms linked to a a common parent subform which is below a
main form.
Based on the field values which are passed from the parent subform I need to
query the values in the child subform table 1 and show them as record source
in subform two.
I have a query with criteria
Table Parent table:
Field Criteria
[Forms]![child form name]![Form Field]
How ever its not able to recognise this criteria and is taking them as a
parameter.
I want to know how to give the Form field in the criteria so that the query
Identifies them from the corresponding form fields
Please help me how to solve this case.

Thanks
Manohar