Hi and welcome,
DON'T DO THAT, 'cause it's a very messy way of doing so. The are tons of tutorials on the internet regarding this matter, so a quick google search wouldn't have hurt.
To accomplish this, you'll need greater control over your sounds, so coding would be an easy way out. To do this, presuming you already have a Sound file in your Library, find it there (in your Library, that is), right-click it, press Properties (or Linkage in Flash 8), expands Show Advanced, tick/check Export for ActionScript, and in the Identifier field, type in something like,
sound1, and press OK. Repeat this for your second sound file, but give it a unique identifier name, like,
sound2.
Presuming that you have 2 buttons on your Stage, click on one of them, open Properties Panel [CTRL+F3], and in the textfield labeled Instance Name, type in something like,
song1_btn. Repeat with the second button, but give it a unique Instance name, such as,
song2_btn.
Finally, select your Frame and open Actions Panel [F9], and type this:
Actionscript Code:
sound1 = new Sound();
sound1.attachSound("sound1");
sound2 = new Sound();
sound2.attachSound("sound2");
song1_btn.onPress = function(){
sound1.start();
sound2.stop();
}
song2_btn.onPress = function(){
sound2.start();
sound1.stop();
}
In the first 4 lines, we create 2 Sound objects, to control each sound individually, and attach the corresponding sounds to the Sound objects (in layman's terms, we assign sound1 and sound2 from the Library to the 2 variables, so that we can play/pause them whenever we want). Next, we make song1_btn and song2_btn do something when they are pressed, and in this case, for song1_btn, we start playing sound1 and stop sound2, but for song2_btn, we start playing sound2 and stop sound1.
This may be really confusing for you, as I'm just throwing a lot of difficult code for a new beginner like you, but this is an easy outway to solve your problem. The more suitable way for you, but more time-consuming and messy, would be to add each sound in their own movieclips on the Timeline, either set the sound to Stream or use stopAllSounds() command to stop all sounds, and then control the timelines of the movieclips with the songs to play/stop them.
Hope this helps, nonetheless :)