I need to update a form field from an inline frame javascript

Hi there.

It's not really easy for me to post the entire code for this, so I will try to clearly describe my problem...

I need some help rigging up a javascript to update a form field in my main form from an inline frame href..

On my main html document, my main form's id is ...  <form id='adm_edit' ... etc.. >

The form field that I want to update is ...

<input id='txtAddress_Code'>

Now, the user clicks a link on the main page which opens a lookup form inside of an inline frame .... They can do a lookup in our database there.  

I am trying to update the value of the form field in the main form from my inline frame...

So, I am trying to update  adm_Edit.txtAddress_Code.value in a javascript function in my inline frame page's code.

I basically want to have a jscript line that does...

??????.adm_edit.txtAddress_Code.value = 12345;

But I do not know how to correctly set the ??????? part ... is it self or frames[ .. or ... ???

Please help.

Thx Scott