How To Make Buttons Work (Help)

[Dreamscape]

Hi guys. i want to make this little program so i want to make save and cancel buttons work. for example with save button i want program to save this file in .txt format in location which i choose. how can it be done help me :( :(... there is a screen:

http://image.geotorrents.com/images/23100148871113772687.jpg