JavaScript: Custom setTimeout function to take arguments

Problem:

window.setTimeout method doesn't give easy way to pass object type argument to the timeout method. And it may cause memory leak too. To avoid this, I have written a simple script which does the same thing.

  
  var PKTimer = new function()
  {
    this.timeoutCnt = 1;
  }

  PKTimer.setTimeout = function(callFn, thisObj, argArr, timeWait)
  {
    if(argArr === null)
    {
      return setTimeout(callFn,timeWait);
    }
    var uniqueId = 'pkt' + PKTimer.timeoutCnt++;
    PKTimer[uniqueId] = [callFn, thisObj, argArr];
    return setTimeout("PKTimer.timeoutAction('" + uniqueId + "')", timeWait); 
  }

  PKTimer.timeoutAction = function(timeOutId)
  {
    var callInfo = PKTimer[timeOutId];
    if(!callInfo)
    {
      return;
    }
    var callFn = callInfo[0];
    var thisObj = callInfo[1];
    var callArg = callInfo[2];
    if(!(callFn instanceof Function))
    {
      callFn = thisObj[callFn];
    }                     
    callFn.apply(thisObj, callArg);
    delete PKTimer[timeOutId];
  }



  function sum(a, b, c)
  {
    alert("Sum: " +  (a + b + c));
  }


  function MathClass(a, b, c)
  {
    this.a = a;
    this.b = b;
    this.c = c;
    this.sum = function()
    {
      alert("MathSum: " + (this.a + this.b + this.c));
    }
  }

  var mathObj = new MathClass(4, 5, 10);
  PKTimer.setTimeout(sum, null, [4, 5, 6], 3000);
  PKTimer.setTimeout(mathObj.sum, mathObj, [], 6000);

Kovil Pillai P.