[Zope] Getting error assigning sequence-item to REQUEST

Can anyone tell me why the following <dtml-in "_.string.split(tune_name,'|')"> <dtml-if sequence-start> <dtml-call expr="REQUEST.set('tune_name',sequence-item)"> raises the error "Error Type: Name Error Error Value:sequence" It is the last line which raises the error. This is the error I would expect if I was trying to use a variable which wasn't in the current namespace so I am confused why I cannot use sequence-item in this way. Can anyone tell me the correct syntax (and why ) ? Thanks in advance Richard Richard Moon richard@dcs.co.uk