stop song and play song

Hi im trying to play a song when i click a paper with this code :

 var papelsonido : AudioClip;
 
 
 function OnMouseDown (){
 
 //Play Key Pickup Sound
 if (papelsonido)
     AudioSource.PlayClipAtPoint(papelsonido, transform.position);
 
     }

that script works fine when i press a paper and the song play it self,, but when i attach that script to another paper, i cant hear the second paper i press ... so my question is this

how i can play a song and when i press another paper that song stops and play the new one ...

thanks a lot