QuickSort algorithm Java?

public class QuickSort {

public static void main(String a[]) {

int i;
int array[] = { 12, 9, 4, 99, 120, 1, 3, 10, 13 };

System.out.println("Values Before the sort:\n");
for (i = 0; i < array.length; i++){
System.out.print(array[i] + "  ");
}


quick_srt(array, 0, array.length - 1);
System.out.println("");
System.out.print("Values after the sort:\n");

for (i = 0; i < array.length; i++){
System.out.print(array[i] + "  ");
}
}

public static void quick_srt(int array[], int low, int n) {
int lo = low;
int hi = n;
if (lo >= n) {
return;
}
int mid = array[(lo + hi) / 2];
while (lo < hi) {
while (lo < hi && array[lo] < mid) {
lo++;
}
while (lo < hi && array[hi] > mid) {
hi--;
}
if (lo < hi) {
int T = array[lo];
array[lo] = array[hi];
array[hi] = T;
}
}
if (hi < lo) {
int T = hi;
hi = lo;
lo = T;
}
quick_srt(array, low, lo);
quick_srt(array, lo == low ? lo + 1 : lo, n);
}
}

Below is the output.....


Values Before the sort:

12  9  4  99  120  1  3  10  13

Values after the sort:

1  3  4  9  10  12  13  99  120