Random Function AS2

programming flash
1

hello how can i make this function to run in random mode.

switch (section){

case "BlueState" :
gotoAndPlay("bann1");
break;

}

i mean , when i open the .swf it should run in random , “bann1” , “bann2” , “bann3” then again “bann1” an so on … only when i restart the swf. it should swich .

Thanks a lot.