Python selenium checkbox click does not work

Hey im using python selenium to download data from table. But when im want to prepare data i cant select a checkbox 'toggle all'....

im geting on page:

browser.get("http://ift.tt/2n8uAbY")

click 'select columns for table'

browser.find_element_by_xpath('//*[@id="showColsButton"]').click()

and here we are checkbox ;toggle all'...

browser.find_element_by_xpath('//*[@id="selectFieldsList"]/thead/tr[2]/td/input').click()

Realy tryed xpath, css selector....

and here we are html fragment:

<table class="selectFieldsList" id="selectFieldsList">

<thead>
        <tr><td colspan="2" align="center">
        Select Fields using the Checkboxes<br>
        <input type="submit" value="Submit" name="fieldSubmit" id="submitMe" class="submitMe">
    </td></tr>


 <!--  add a select all option -->
       <script language="JavaScript">
       function toggle(source) {
           checkboxes = document.getElementsByName('selectField');
           for(var i=0, n=checkboxes.length;i<n;i++) {
              checkboxes[i].checked = source.checked;
           }
       }

       </script>
       <tr><td> <input type="checkbox" onclick="toggle(this)"> Toggle All<br> </td></tr>
<tr><td>* = required column</td><td>&nbsp;</td> </tr>

<tr><td> <input type="button" id="entityFieldSelectorToggle" value="Expand All Fields"> </td>
</tr></thead>
<tbody>