Hello Predrag and Michael.
Thanks for letting me know to open a new thread about my question. I "may" have resolved the issue for now. What happened was when I was inserting the code that was suggested in the text field in wordpress, when I click on publish, it goes to a white screen. So i hit the back button of safari and removed the code id="popup". The page saves after i hit publish and then i include the code and publish it again and doesn't go to white screen. It is an odd behaviour and i couldn't tell if another plugin is causing this inconsistency and I don't want to risk turning off and on the plugins that I have because all of them are important and I am scared to mess things up.
So far, your plugin works exactly what I need and it saved my sanity. I am sure that i will have questions until i put my website online. For now, i am at peace with your plugin and i am a happy customer.