Opening a URL from a dynamic text field

I have an external text file I use to load captions for my slideshow I’m using to present images in my portfolio I’m making for my senior seminar class. I want it to open up a url to show an expanded image of the thumbnail I added.

In my external text field I have three things:
&caption1=Problem: Create a photo with things that typically don’t go together
&credit1=Solution: Taking photos and using Photoshop to create a unique photo
&software1=Software: Photoshop CS3

I thought if I added a 4th dynamic text field (url_txt) and used &url1= for each cite it would load. I even made the field render text as HTML but it doesn’t work.

What can I do to fix this?

Thanks!