mergeSort-merge.js

function merge(array, lower, half, upper){
	var left = [], i = 0;
	while (i < half - lower + 1){
		left.push(array[lower + i++]);
	}
	left.push(Number.MAX_VALUE);

	var right = [], j = 0;
	while(j < upper - half){
		right.push(array[half + j++ + 1]);
	}
	right.push(Number.MAX_VALUE);

	i = j = 0; 
	for(k = lower; k <= upper; k++){
		array[k] = left[i] < right[j] ? left[i++] : right[j++];
	}
}