function uniquerand(required,maxnum)
{
 if (required > maxnum) {
   alert('too many required');
   return;
 }

 var found = 0;
 var retnums = Array();

 while (found < required) {

  var unique = false;

  var anum;

  while (!unique) {
  
    anum = Math.floor(maxnum*Math.random());

    unique = true; // initial assumption

    for(var i = 0; i < found; i++) {
      if(retnums[i] == anum) {
        unique = false;
        break;
      }
    }
  } 

  retnums[found] = anum;

  found++;
 }
 
 return retnums;
}