Slow shuffle for large arrays

I'm implementing the Fisher-yates shuffle in a Photoshop script. I want to create an array of n unique random elements from a maximum of about 99999. Where n is a small value but could be up to to maximum.

With maximum of under a thousand this is fine (runs in milliseconds), but considerably much slower for 10,000 (about 20 seconds).

Is there a better/faster way to do this? Bear in mind that'll it'll need to be in ECMAScript.

var maxNumber = 99; 
var numToGenerate = 5; 

var bigShuffle = shuffle(maxNumber);
var randomNumbers = bigShuffle.slice(0, numToGenerate);

alert(randomNumbers);


function shuffle(m)
{

   var temp;
   var rnd;

   // create an empy array
   var arr = new Array();
   var d = m + "";
   d = d.length;

   for(var i = 0 ; i < m; i++) 
   {
      arr.push(i);
   }

   while (m)
   {
      rnd = Math.floor(Math.random() * m-=1);
      // And swap it
      temp = arr[m];
      arr[m] = arr[rnd];
      arr[rnd] = temp;
   }

  return arr; 
}