How to disable all the controls on the page after the countdown timer stops in asp.net?
<p>I have tried to disable the next button in the following code but its not working....pls help... </p>

<pre><code>     protected void timer1_Tick(object sender, EventArgs e)
    {
        CurrentTime = CurrentTime.AddSeconds(-1);
        LblTime.Text = "Time Left: " + CurrentTime.TimeOfDay;

        if (CurrentTime.TimeOfDay == DateTime.MinValue.TimeOfDay)
        {
            LblTime.Text = "Oops!! Time Up";         

            timer1.Enabled = false;

            btnnext.Enabled = false;

        }
</code></pre>
