[Zope] Odd key erro in ZSQL

Hi List, I have a ZSQL method selectedCentreQual that picks up parameters from the session: - select * from mv_CTR_QUAL WHERE CtrRef = <dtml-sqlvar expr="REQUEST.SESSION['CtrRef']" type="string"> This method seems to work fine, and returns a single record. When I try to use the method in a page template, e.g.: - <span tal:replace="here/selectedCentreQual/QualID">QualID</span> I get: - Error Type: KeyError Error Value: '_r' Can anyone tell me what I am doing wrong? -- Regards, PhilK Email: phil@xfr.co.uk / Voicemail & Facsimile: 07092 070518 "The lyf so short, the craft so long to learne" - Chaucer