Skipping Records in a Transform

From: Sean Carpenter (seancarpenter_at_NOSPAMprometrics.com)
Date: 11/16/04 

Date: Tue, 16 Nov 2004 16:13:59 -0500

I have a document that contains sales transactions in a format similar to
this:

<Trans TransDate="1/1/2004">
    <Account>xxx</Account>
    .....
    <SaleAmt>10</SaleAmt>
</Trans>
<Trans TransDate="1/2/2004">
    <Account>xxx</Account>
    .....
    <SaleAmt />
</Trans>

When transforming this data, I'd like to skip any Trans elements that have
an empty SaleAmt (these records would not be in the destination document).
I'm stuck as to how to do this in BizTalk Mapper (or even if that's the
right place to do it). Any help is appreciated.

Thanks,
Sean Carpenter
ProMetrics Consulting, Inc.