Custom Controls & Javascript

I have created a Custom Control and I need to populate 2 fields with data
that I am grabbing from a control on the parent form. I need to use
Javascript to grab the data on the parent form & populate the data in the
custom control. The code that I have below get's the data but can't find the
control on the custom control. Any ideas or proper direction would be
appreciated.

sFName=document.Form1.fldFName.value;
var NameField = document.getElementById(fldQFName);
NameField.value = sFName;

Thanks!

Steve.
.

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