Setting hidden field value eq to a form field value.

[Sharry]

Ok guys help a dumb blond out.
I need to pass the value of a form field to two different file fields.
Here is an example of what I have;

<form name="FrontPage_Form1"
action="http://www.abc.com/cgi-bin/formdata.cgi" method=post>
First Name
<input type="text" name="First_Name" size="20" value="">
<input type="hidden" name="SendTo"
value="document.FrontPage_Form1.First_Name.value">
<input type="submit" name="cgifunction" value="Submit">
</FORM>

The file field "First_Name" saves fine
but....
The file field "SendTo" saves the wording
"document.FrontPage_Form1.First_Name.value" instead of the value of the
First_Name field.

Where am I going wrong?

Thanks in advance.
Sherry