hi all,
I have a Real Player executable file with extension .bin. When I double click to install this file the following message appears.

"The filename "RealPlayer10GOLD.bin" indicates that this file is of type "unknown". The contents of the file indicate that the file is of type "executable". If you open this file, the file might present a security risk to your system.

Do not open the file unless you created the file yourself, or received the file from a trusted source. To open the file, rename the file to the correct extension for "executable", then open the file normally. Alternatively, use the Open With menu to choose a specific application for the file."

I also tried:
# chmod +x filename.bin ( or chmod 777 filename.bin)
# ./filename.bin

Then the error comes
./RealPlayer10GOLD.bin: error while loading shared libraries: libstdc++.so.5: cannot open shared object file: No such file or directory.

(the file name is RealPlayer10GOLD.bin)

Can any one help me. I am new to linux and want a player for linux which can play .mp3, .mpg, mpeg, avi etc files etc.

You'll need to install libstdc++ before you install RealPlayer. There should be a package for your distro somewhere.