Object reference not set to an instance of an object
<p>I create next button but doesent work. The error says: Object reference not set to an instance of an object. 
Please help</p>

<pre><code>private void nextbutton_Click(object sender, EventArgs e)
    {
        if (counter&lt;dt.Rows.Count - 1)
        {
            counter++;
            cbSifra.Text = dt.Rows[counter][0].ToString();
            cbSSP.Text = dt.Rows[counter][1].ToString();

        }
    }    
</code></pre>

<p>dt is never assigned to, and will always have its default value null, this is warning about the code. and i can't solve it. the same problem with the previuos_button    – </p>
