If statement problem

[Mr.Joker]

Ok. I have one button and one textbox. Now, user should enter how old he is. I want to make statement that if he is older then 13 some messagebox will popup. Problem is that with VB i know how to do that but in C# its not working on that way. Here is the code I made:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            int[] num = {1,2,3,4,5,6,7,8,9,10,11,12,13 };
            for (int i = 0 ; i<=13;i++) {
                if (textBox1.Text > num[i].ToString())
                {
                    MessageBox.Show("You are enough old to join us.");
                }
            }

        }
    }
}

What can be the problem?