checkAll by attribute not firing?
<p>Im confused why this isnt working and am not able to debug </p>

<p>I have a set of checkboxe's grouped by an attribute value
and have a checkall class at the foot of each group with matching attribute value when i click this i want to toggle the other checkboxs to same state </p>

<p>jquery</p>

<pre><code>$(function () {
    $('.checkall').click(function () {
        var myactivemonth=$(this).attr("data-mymonth");
        console.log(myactivemonth);
        var myactivebox="a_"+myactivemonth;
        $('checkbox[data_mymonth=myactivemonth]').attr('checked','checked');
});
</code></pre>

<p>html </p>

<pre><code>&lt;input id="alloInv" class="tip_trigger" type="checkbox" data-mymonth="a_October2012" title="13.94" value="2018441" name="alloInv"&gt;
&lt;input id="alloInv" class="tip_trigger" type="checkbox" data-mymonth="a_October2012" title="10.94" value="201845" name="alloInv"&gt; 
&lt;input class="checkall" type="checkbox" data-mymonth="October2012"&gt;
</code></pre>

<p>IT appears all ok but the boxes aren't ticking :(</p>
