Add more website into the menu

Hi, im making website for movies, i bought a premade theme and when im making a new post i can select from where to take the movie and then just put in the url, now when i found another website that provide some nice series and movies i have no idea how i can add that to my list :/ The code for a few sites looks like this

define("YOUTUBE_TARGET", "<object type=\"application/x-shockwave-flash\" data=\"http://www.youtube.com/v/###VID###\" width=\"".GENERAL_WIDTH."\" height=\"".YOUTUBE_HEIGHT."\"><param name=\"movie\" value=\"http://www.youtube.com/v/###VID###\" /><param name=\"autostart\" value=\"true\" /><param name=\"wmode\" value=\"transparent\" /></object><br />");

	define("YOUTUBE_LINK", "<a title=\"YouTube\" href=\"http://www.youtube.com/watch?v=###VID###\">YouTube ###TXT######THING###</a>");

	define("GOOGLE_TARGET", "<object type=\"application/x-shockwave-flash\" data=\"http://video.google.com/googleplayer.swf?docId=###VID###\" width=\"".GENERAL_WIDTH."\" height=\"".GOOGLE_HEIGHT."\"><param name=\"movie\" value=\"http://video.google.com/googleplayer.swf?docId=###VID###\" /><param name=\"wmode\" value=\"transparent\" /></object><br />");

	define("GOOGLE_LINK", "<a title=\"Google Video\" href=\"http://video.google.com/videoplay?docid=###VID###\">Google ###TXT######THING###</a>");

	define("MYVIDEO_TARGET", "<object type=\"application/x-shockwave-flash\" data=\"http://www.myvideo.de/movie/###VID###\" width=\"".GENERAL_WIDTH."\" height=\"".MYVIDEO_HEIGHT."\"><param name=\"movie\" value=\"http://www.myvideo.de/movie/###VID###\" /><param name=\"wmode\" value=\"transparent\" /></object><br />");

	define("MYVIDEO_LINK", "<a title=\"MyVideo\" href=\"http://www.myvideo.de/watch/###VID###\">MyVideo ###TXT######THING###</a>");

	define("CLIPFISH_TARGET", "<object type=\"application/x-shockwave-flash\" data=\"http://www.clipfish.de/videoplayer.swf?as=0&amp;videoid=###VID###&amp;r=1\" width=\"".GENERAL_WIDTH."\" height=\"".CLIPFISH_HEIGHT."\"><param name=\"movie\" value=\"http://www.clipfish.de/videoplayer.swf?as=0&amp;videoid=###VID###&amp;r=1\" /><param name=\"wmode\" value=\"transparent\" /></object><br />");

PHP:

And the website i would like to add is http://megavideo.com/ so i can add movies from there aswell

Would really appriciate some help since im totally lost here