how to accomplish relation between select control and dropdown list in firefox3.

Hi,

I have 2 scenarios, in first I have select control and I need to get
hold of combobox dropdown, 2nd one is reverse of this.
In firefox2, I was using nsiframe interface for this, but with
firefox3 nsiframe() is unfrozen or internal, so I can't use it.
Could you please, guide me, how to accomplish this.

In firefox2, I for getting combobox() dropdown frame select control, I
had following code :

I get frame coresponding to select element by   comboFrame->GetDropDown
(&dropdownFrame);
Next I get the widget corresponding to the frmae by  dropdownFrame-
>GetWindow();

But in firefox3 I am tied as I am not able to use nsiframe()
interface.

2nd case, from combobox doprdown, I get select element corresponding
to it by following code.

I have instance of nsIFormControlFrame corresponding to drop doen
frame, so I use GetFormContent API on nsIFormControlFrame.
controlFrame->GetFormContent(content) ;

But in firefox3, nsIFormControlFrame interace no more has
GetFormContent API.

Please suggest me how can I get over it.

--
Thanks
Srinivas