Generate Random String

function generateRandomString(strlen:Number):String{
  var chars:String = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
  var num_chars:Number = chars.length - 1;
  var randomChar:String = "";
 
  for (var i:Number = 0; i < strlen; i++){
  randomChar += chars.charAt(Math.floor(Math.random() * num_chars));
  }
  return randomChar;
}
trace(generateRandomString(7));