How do you force form email in Plain text

[Andy Reed]

I have a form with a button which validates the fields
using JScript then emails via {location.href = "mailto:
etc.}

The email client is fired up but the new email is always
in Rich Text format. How do I force the email client to
use Plain text format?

I have used encytpe = "text/plain" in the form but that
doesn't help. There must be a parameter to the emailto:
call which I don't know?

Reason for this? - I get strange line throws when I don't
expect them in Rich Text email so am hoping Plain is more
reliable.

Thanks.