You can add additional columns to search by in your address book by doing the following:
1. Login to Webmail.
2. Click the 'Address book' icon.
3. Click the 'Option' icon at the top of the page.
4. Click the blue 'Column Option' link.
5. Put a 'check' in each of the boxes that are available that you want to be able to search by. For example, if you want to search by email address, first name, birthday and work city only, then put a 'check' by clicking the box next to those options.
6. Click the 'Save Option' button at the bottom.