ValueChanged event in windows XP
<p>I have an ValueChanged event where I am checking dates and displaying a message to user and I set the value of the DateTimePicker to another value. This is the event:</p>

<pre><code>private void dtpStartDate_ValueChanged(object sender, EventArgs e)
{
    if (frmDate.Value &lt; this.minDate)
    {
        MessageBox.Show("Date not found");
        frmDate.Value = previousValue;
        return;
    }
}
</code></pre>

<p>This works fine in Windows 7 but it displays the message box two times in Windows XP. How can I fix it?</p>
