> What is wrong with that code ? I´m trying to pass a variable EdtCodigo 
> as a parameter in expression:
> <dtml-call 
> expr="RESPONSE.redirect('02_contratos_altera?codigo=<dtml-var 
> EdtCodigo>')">
You are using DTML inside Python expression.
try
<dtml-call expr="RESPONSE.redirect('02_contratos_altera?codigo=%s)' % 
_['EdtCodigo']">