make email field REQUIRED when UNREGISTERED USER want to make a question

Question

In my website i'm allowing unregistered users to ask questions , and there is an email field in the ask page . but i want to make it not allowed to ask question without putting the email . thank you

Answer 1

You can deal by making filter plugin including filter_question().

Reference:
http://www.question2answer.org/modules.php
http://www.question2answer.org/modules.php?module=filter
http://www.question2answer.org/qa/24985/prevent-duplicate-question-titles

Comments

thank you for trying to help me , but it's still unclear .. i want to make sure that an email is provided . can you give me the code and tell me where i have to put it ?