Things to take away from this thread...
Remember to clear your cache when changes have been made, or disable caching in your browser during production/testing.
Learn how to identify missing files/incorrect paths using Firebug (which you hopefully still have installed). Practise with the second video link in your page (Gorilla pic).
Go to your page in Firefox.
Click on the Net tab. The HTML button in the menu below should be highlighted.
In the list below you'll see a number of file names, prefixed by "GET". The ones in red are files that the browser has tried to download but the server has been unable to find. The gorilla_video.png is not listed because it will only download when the link of which it is the href is clicked.
Click the Gorilla link.
"GET gorilla_video.png" will now appear in the list,. 404 Not Found.
Hover over the "GET gorilla_video.png" in the list and the (incorrect) absolute path to the file will be shown.
In future, every time something is missing from your page or doesn't work as intended, check in Firebug first. Aim to identify and fix broken paths by yourself, every time.
Editing paths on the fly in Firebug
Click on the Inspect tool and then on the Gorilla pic. The HTML tab will become active and the img element selected. Click on the href attribute of the img's parent anchor.
You can now edit the path. Change "images/gorilla_video.png" to "/construction/images/gorilla_video.png" and click outside the edit box to complete the edit.
Now click on the name attribute. Change "/construction/videos/gorilla.flv" to "videos/truck.flv" (we know that file exists), Click outside to complete the edit.
Click on the Gorilla again. The truck video will play.