i installed mplayer it installed successfully but when i click the mplayer button it says either " can not find viewer capable of vieing file" or "gmplayer not found" how do i fix this

Well, I'm no expert but I can tell you a few things to try. Open a console and type "gmplayer" to see if it will launch from there. If it does it's installed properly. If it doesn't, it was probably installed in a location that was not in your path (the default locations where you look for things). You can type "locate gmplayer" to find where the file lives. Do a google search on setting your path for your distribution, and take it from there. I've never had much luck with gnome's file association settings, so if the file IS in my path, I usually just create a new launcher on a tool bar. Set the command to be gmplayer, or the full path to the file if you need to (ex. /usr/bin/gmplayer if that's where locat told you it lives). Choose an icon for it, and away you go. Hope this helps

did you ./configure --enable-gui if you did you will need fonts and a default skin which can be downloaded at mplayers home page. You can aviod alot of trouble if you'd bother to read the install instructions.