Method date_range

* look for a range of date values for the given column, and return * values to be added to the WHERE clause * * This is used when you have a column like "invoice_date" in the report, * but what you really want to search for is a range of dates between a given * start and end date. * * To do that, create form fields with _start and _end added to the name, * a

($col_name, $var_name, $expression)