title: Textbox inside a gridview and its value not reflecting on server side
body: <p>I have a textbox column in gridview where that column was filled with a predefined database value but some of the cells have a null value assigned. I have to update those cells only but when I used, it appears a null string in <code>Textbox1</code>.</p>
  
  <p>I have also bind grid on <code>if(!ispostback)</code> in page <code>load()</code> but got same result.
  What I am missing here?</p>
  
  <pre><code>TextBox TextBox1 = row.FindControl("txt1") as TextBox;
  </code></pre>