Scan attachment names for banned extensions

Hi all

I have tried to modify the "Attachment Alert" Zimlet to detect types of attachments we do not want sent out (Microsoft Office editable) - we only allow PDFs out of the company.

In order to do this I have used the list of words in AttachmentAlert_attach in com_zimbra_attachmentalert.properties. I am then trying to scan the list of attachments for these extensions. My relevant lines of code are:

var attachArray = mail.getAttachmentInfo();

var newMailArry = attachArray.contains(attachWord);where attchWord is from the array of banned extensions.However this seems to crash - the buttons grey and no popup window.

Any ideas?