Merge Sort in C#

public class MergeSort {

private int[] arrClone;

public void sort(int [] arr) 
   {
    arrClone = arr.Clone() as int[];
    sort(arr, 0, arr.Length - 1);
}

private void sort(int[] arr, int low, int high) 
   {
    
    if(low < high) {
        int mid = (low + high) / 2;
        
        sort(arr, low, mid);
        sort(arr, mid + 1, high);
        
        merge(arr, low, mid, high);    
    }
}

private void merge(int[] arr, int low, int mid, int high) 
   {
    int i,j,k;
    i = low;
    j = mid + 1;
    
    for(k = low; k <= high; k++) 
       {
        arrClone[k] = arr[k];
    }
    
    for(k = low; k <= high; k++) 
       {
        if ( i > mid ) {
            arr[k] = arrClone[j];
            j++;
        }
        else if ( j > high ) {
            arr[k] = arrClone[i];
            i++;
        }
        else if ( arrClone[i] > arrClone[j] ) 
           {
            arr[k] = arrClone[j];
            j++;
        }
        else 
           {
            arr[k] = arrClone[i];
            i++;
        }
    }
}
}