Hi.
If you're only looking for a solution for that specific test string, you can use the fact that the second match line is the only one that contains alt="Green img" to identify it:
id="zoom-product-image" src="([^"]*\.jpg)" alt="Green img"
If you're interested in a more general solution to match the second line without relying on a specific value in it, I can provide that along with a good explanation, either in a document including screenshots or with a quick Skype video call when it's convenient for you.
Michael Tomilson