title: Onclick event on input type image submits form
body: <p>I got an input type image with a javascript onclick event attached to it.
  Everytime I click the image it submits the form. I've already added the "return false", buts that that doesn't solve the problem.
  Here is my code:</p>
  
  <pre><code>&lt;input type="image" onclick="incrementValue(@i)" value="+" /&gt;
  </code></pre>
  
  <p>Javascript</p>
  
  <pre><code>function incrementValue(n) {
  
      var id = 'txtAantal' + n;
      var value = parseInt(document.getElementById(id).value, 10);
      value = isNaN(value) ? 0 : value;
      value++;
      document.getElementById(id).value = value;
  
      var totaal = parseFloat(document.getElementById('txtTotaal').value, 10);
      var prijs = parseFloat(document.getElementById('txtPrice' + n).value, 10);
  
      document.getElementById('txtTotaal').value = totaal + prijs;
  
      return false;
  }
  </code></pre>