Contact Chapters in your area -
When you use the Chapter Search on this web site and you are logged in as a member, you are given the option to quickly contact any chapter in your area. Click the "contact this chapter" link and a simple form will pop up. All you need to do is click the option that tells them you are having an event and you wish to invite them to attend. Your chapter contact information will automatically be sent to them along with your invitation.
This form does not allow you to send specific event details, however. To do that, you need to wait for them to contact you and show interest in the event.