[Zope] Lines Property and special namespace variable

Hi all, Im trying to changes the contents of a lines property into floating point numbers a la: <dtml-in lines> <dtml-let "_.float(lines)"> <dtml-if "lines > 0"><font color="#006600"></dtml-if> <dtml-var sequence-item> </dtml-in> The contents of the lines property are: 25.32 -16.50 Thanks in advance.