how to change default form submit action and fields?

[Muphet]

i am using custom forms with few hidden and select fields. i am using onSubmit function to get all field values then call meteor method to insert data. for some reason, submit button doesn't work for me at all, not even error logged. how can i set custom submit action for the form?

also, is there way to add custom fields to modal? like select/radio/datepicker etc