function merge(left,right){

	var results = [];
	var left_index = 0;
	var right_index = 0;
	var len_r = right.length
	var len_l = left.length
	while(left_index < left.length, right_index < right.length){
		if (left[left_index] <= right[right_index]){
			results.push(left[left_index]);
			left_index ++;
		}
		else{
			results.push(right[right_index]);
			right_index ++;
		}
	}
	if (left){
		results.concat(left.slice(left_index, len_l));
	}
	if (right){
		results.concat(right.slice(right_index,len_r));
	}
	return results;
}

// var a = [0,1,2,3]
// var b = [4,6,1]
// console.log(merge(a,b));

// var myList = [0,1,2,3];
// var res = [5]
// var len = myList.length

// s = res.concat(myList.slice(1,len));
// console.log(s);

function mergeSort(myList){
	len = myList.length;
	//console.log(myList)
	if (myList.length < 2){
		return myList;
	}

	var middle = parseInt(myList.length/2);
	var left = myList.slice(0,middle);
	var right = myList.slice(middle,myList.length);
	console.log(myList)

	return merge(mergeSort(left),mergeSort(right));

}

var myList = [0,1,5,8,2,4];

console.log(mergeSort(myList));