implement insert

var insert = function(array, rightIndex, value) {
    var i;
    for (i = rightIndex; i >= 0 && array[i] > value; i--){
        array[i+1] = array[i];
    }
    array[i+1] = value;
};

var array = [3, 5, 7, 11, 13, 2, 9, 6];

insert(array, 4, 2);
println("Array after inserting 2:  " + array);
Program.assertEqual(array, [2, 3, 5, 7, 11, 13, 9, 6]);

insert(array, 5, 9);
println("Array after inserting 9:  " + array);
Program.assertEqual(array, [2, 3, 5, 7, 9, 11, 13, 6]);

insert(array, 6, 6);
println("Array after inserting 6:  " + array);
Program.assertEqual(array, [2, 3, 5, 6, 7, 9, 11, 13]);