title: Clear Gridview each time click a button
body: <p>My code populate 1st row inside the grid view. After page loads and type 1st row data I can populate 10 rows by click the copyButton. but when I change 1st row data and click again it shows 20 rows. But I need only 10 rows that has only updated data which is new entry. How can I update grid view when i click second time by deleting the old record and populated by 1st new entered values?</p>
  
  <p>Example:</p>
  
  <pre><code>ID  Explanation  teacher
  --- ----         --------
  0   hello        45       
  1   hello        45
  2   hello        45
  .   .            .
  .   .            .
  .   .            .
  10  hello        45
  </code></pre>
  
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