Open a URL if it isn't already open

[coolmoods]

I created a workflow that opens up a few URLS in my default browser (Chrome) that I always need for my workday. It's real handy, but it often creates duplicate tabs since Chrome will remember the last set of tabs you had open when launching.

 

I'd like to tell Alfred to open a URL if it isn't already open. I'm guessing I would need to do that through an AppleScript or something, but I'm not sure how. Any tips?