title: Calculating sum from a table in an iframe
body: <p>I have a main page and a sub page (frame) one. The frame contains a table that contains numbers in a column. I want to sum up these numbers and get the result from the main page.</p>
  
  <p>Now my problem is just I don't know how to access the <code>&lt;input&gt;</code>s in the frame table.</p>
  
  <pre><code>&lt;iframe id="iframe_form" name="iframe_form" src="ServicesList_guest_form.php"
  frameborder=0 style="width:540px;height:900px;position:absolute;top:710px;" &gt;&lt;/iframe&gt;
  </code></pre>
  
  <p>The file <code>ServicesList_guest_form.php</code> contains</p>
  
  <pre><code>...
  &lt;form id="f1" action="save.php" ...&gt;
    &lt;table id="mytable" ... &gt;
       &lt;tr&gt;&lt;td&gt;&lt;input type="number" name="val1"&gt;&lt;/td&gt;&lt;/tr&gt;
       &lt;tr&gt;&lt;td&gt;&lt;input type="number" name="val2"&gt;&lt;/td&gt;&lt;/tr&gt;
       &lt;tr&gt;&lt;td&gt;&lt;input type="number" name="val3"&gt;&lt;/td&gt;&lt;/tr&gt;
       ...
    &lt;/table&gt;
  &lt;/form&gt;
  ...
  </code></pre>
  
  <p>Thank you for help</p>