Recursion in Java

So I'm working on some sorts here, merge and quick. My merge works lovely. I get a stack overflow error with my quicksort method, so I'm not... recursing properly or something. Never exits the recursion. Ignore showProcess, that's for something else. l is the length of the array minus one.

 Quicksort

Code:

public static void quickSort (boolean showProcess, int low, int toSort[], int length){
                int lo = low;
                int hi = length;
                if (lo >= 1)
                {
                        return;
                }
                else
                {
                int pivot = toSort[lo];
                while (lo < hi) {
                        while (toSort[lo] <= pivot && lo <= length && hi > lo)
                                lo++;                                    
                        while (toSort[hi] > pivot && hi >= low && hi >= lo)
                                hi--;  
                        if (lo < hi)
                        {
                                int temp = toSort[lo];
                                toSort[lo] = toSort[hi];
                                toSort[hi] = temp;
                        }
                }
                if (hi < lo)
                {
                        int temp = hi;
                        hi = lo;
                        lo = temp;
                }
                quickSort(showProcess, low, toSort, lo - 1);
                quickSort(showProcess, lo + 1, toSort, length);
                }
        }