title: Add a button with onclick event in infowindow
body: <p>I am trying to add a button with onclick event in the infowindow of google map api v3 </p>
  
  <pre><code>        var cont = "&lt;div&gt;&lt;h4&gt;&lt;b&gt;Transformer&lt;/b&gt;&lt;/h4&gt;&lt;label&gt;Name: &lt;/label&gt;"+this.transformerName.charAt(0).toUpperCase()+this.transformerName.substring(1)+"&lt;br&gt;&lt;label&gt;Site No: &lt;/label&gt;"+this.siteNo+"&lt;br&gt;&lt;label&gt;Substation No: &lt;/label&gt;"+this.substationNo+"&lt;br&gt;&lt;label&gt;Transformer No: &lt;/label&gt;"+this.unitNo+"&lt;br&gt;&lt;button onclick='voltagemodel()'&gt;voltagetrend&lt;/button&gt;&lt;/div&gt;";
      console.log(cont);
      infowindow.setContent(cont);
  </code></pre>
  
  <p>but the onclick event is not firing kindly help</p>