Scripting for browser plugin

We need scripting to our browser plugin (bid only for scripting): When watching video on tube websites (for example youtube) it will add a small banner on the left side of the video offering you to download a video (banner will be an iframe). It will be similar to tooltip: [login to view URL] just with iframe and will be there permanently. Here is the samle version of vertical banner: http://alltube[xxx][login to view URL] (please remove [xxx]), wewant to create horizontal banner now and thats what we need scripting for right now (horizontal will be on the left side of a video covering any other elements that are there, working on all tube websites regardless of styles etc.). We need to inject iframe to an existing video site (as above we do not know the styles and js already used). We have no idea what styles site uses so it must work universally on all websites. It has to be placed on the left side of the video and has height of that video. When user scrolls the page it moves too and is still taped in the same relative position to the video. And also when user changes window size and so on. As far as I know The only method to do it universally for most of the pages is to use absolute position capture some events and use java script to change its position. You can use any div of iframe for testing puposes. Once again I will clarify because a lot of developers get confused with this: we will inject the code directly to tube site code when user who installed our software watches videos. It will be used to give him the ability to easily download videos. Our plugin will work on all tube websites so we need a script that will be able to work with any site. So when you have our plugin installed and visit [login to view URL] you will have this banner on the left side of video. This will be easy for you if you know how to do it, so if you doubt if you can do it please don't bid. We are looking for the ones that can do it easily. Please write me PM letting me know if you really know how to do it (some description would be nice), also if you need any clarifications please feel free to PM.