2 Answers

offer your help,sense of humor,patience,tell the person other sources  of info.

Greet a customer with a sincere smile and good eye contact.
Politely ask if there is anything you can help the customer find or if there is any particular help the customer needs.
LISTEN to what the customer says, and repeat in your own words what you think you heard. That way you know you and the customer are on the same page.
Help the customer if you are able to do so.  If what the customer wants is beyond your expertise or you do not know the answer, tell the customer that you need to get a more experienced representative to assist.  Take the customer to a location in the business where it will be most convenient for the "expert" to meet with the customer.  
Contact the "expert" as quickly as possible.  
Remain with the customer until help arrives.  Do not leave the customer alone. RUDE.
If you are able, stay when help arrives and learn something new.
ALWAYS thank the customer for patronizing your business and allowing you to be of help.