title: Increment a double value
body: <p>I'm using this part of code in my system.</p>
  
  <pre><code>double countA = 0.00;  
  double countB = 0.00; 
  
  
  if (myrow.grade == "A") 
  { 
    countA += 1.00; 
  }
  else if (myrow.grade == "B") 
  {
    countB += 1.00;  
  }
  
  countALabel.Text = Convert.ToString(countA);
  countBLabel.Text = Convert.ToString(countB);
  </code></pre>
  
  <p>The code is supposed to calculate how many student in my <em>examMarks</em> table that get "A" or "B" and display it using labels. However I keep getting <code>0</code> value even if there are students who get "A" and "B" in my table?</p>
  
  <p>How do i get the increment value?</p>