It's pretty easy: <dtml-call "sql_method(argument1=value1, argument2=value2)"> There's a problem with your SQL-statement:

INSERT INTO plan (field1, field2, field3, field4) VALUES (<dtml-var param1>, <dtml-var param2>, <dtml-var param3>, <dtml-var param4>)

It should be: INSERT INTO plan (field1, field2, field3, field4) VALUES (<dtml-sqlvar param1 type=string>, <dtml-sqlvar param2 type=string>, <dtml-sqlvar param3 type=string>, <dtml-sqlvar param4 type=string>) Andyman