Reversing the Keys and Values in a Hashtable

Here's how to reverse the Keys and Values in a Hashtable. I use the results and overwrite the original ht.Adds.
The results are output into the TextBox txtReversed.Text

protected void btnReverseHash_Click(object sender, EventArgs e)
    {
        Hashtable ht = new Hashtable();
        ht.Add("a1", "Ask");
        ht.Add("a2", "Ask what your country can do for you");
        ht.Add("a3", "Ask what you can do for your country");
        IDictionaryEnumerator _enum = ht.GetEnumerator();
        string sOut = "";
        const string _FRONT = "ht.Add(";
        const string _END = ");\n";
        const string _Q = "\"";
        const string _CS = ", ";
        while (_enum.MoveNext())
        {
            sOut += _FRONT + _Q + _enum.Value.ToString() + _Q + _CS
                          + _Q + _enum.Key.ToString() + _Q + _END;
        }
        txtReversed.Text = sOut;
}