how to set a null value for DefultValue of a property
<p>i have 4 properties
like these</p>

<pre><code>    public string strLastName { get; set; }
    public string strSpeciality { get; set; }
    public string strProfession { get; set; }
    public string strUserName { get; set; }
    public string strPassword { get; set; }
    public string strRegDate { get; set; }
</code></pre>

<p>now how can i set NULL Value for strRegDate property?
i don't want use IF statement,
thanks</p>
