Popup To Internal Code In Same File?

I have code to make a popup via javascript and it works fine, but what actually pops up is an external file that i select (in my case test.html). i want all of the code of test.html to be in my index.html and when i call the popup it doesn't call an external file but instead calls the html code in the internal file (index.html)? possible?

Code:

What's in test.html? it's a form

Why? i need the code of test.html to access some global javascript variables in index.html.