1. What is your script include name?   The way to call script include functions are

new <script>.<method name>(<parameters>);

Also while calling it from conditions, I have always see using javascript before the call. i.e.:

javascript: new <script>.<method name>(<parameters>);

2. Have you confirmed that your function is being called correctly.   I would type a gs.log statement before return to confirm that function call is correct.

- Hardik Vora