Visit by Specific Referrer

For this Active Condition (Visit by specific referrer), what should be entered for the referrer, if say, I want to have a pop-up to show ONLY if the visitor is coming from http://siteA.com or http://siteB.com. [Right now, the default text is "Array."] Or am I misunderstanding what this particular active condition is for?

Please put examples in Installation & Usage Instructions, please! :slight_smile:

Thankyouverymush,,,,