title: How to get cell value if I know column name in gridview
body: <p>I have 'GridView1' and 'label1' like this:</p>
  
  <pre><code>ID___________NAME___________SELECT
  
  1 --------- NAME1 --------- button
  
  2 --------- NAME2 --------- button
  
  3 --------- NAME3 --------- button
  
  4 --------- NAME4 --------- button
  
  lable1 = null
  </code></pre>
  
  <p>If I hit any button in SELECT column, I want display the ID of the people I selected to the label1, for example if I hit button of the first row, it should display: </p>
  
  <pre><code>label1: You have selected people with ID = 1
  </code></pre>
  
  <p>how can I do that?</p>