I want to verify that certain fields in a form have been entered. Here's a code snippet I've tried to use: <dtml-let required="('first', 'last', 'email')"> <dtml-in required> <dtml-if expr="REQUEST.form[sequence-item]"> <dtml-var sequence-item> exists </dtml-if> </dtml-in> </dtml-let> Naturally, I get an error when this is executed, since Python interprets "sequence-item" in the dtml-if as subtracting item from sequence. I thought <dtml-var sequence-item> might work, but apparently that sort of thing is not allowed in an expression. Is there a way to access the value of sequence-item in an expression? If not, how could I go about verifying that form fields are entered correctly? As a side note, is there any good reason that sequence-item isn't spelled sequence_item? Just curious... Thanks, Ben