How to overlay a youtube video over your website

Hello I am trying to figure out how to do the follow

1.Click an image on a page

2.This will overlay a youtube video on top of your current page

3.Clicking any transparent part of the screen will return user back to said page

I have added a screenshot to help illustrate my scenario. Thank you for the help in advance, this is for a side project I am working on!! I guess I need more reputation before attaching an image so I have added a jing screenshot. http://ift.tt/1az3xyP