How to toggle hide/show of all elements with same class name on button click
<a href=# onClick='toggleHist("".$zone."");return false;'>Additional Info</a>

    <table>
    <tr>
    <td>asdfasdf   <div class='zone_1' style='display:none;'>asdfasdf asdfasdf asdfasdf </div></td>
    </tr>
    <tr>
    <td>
     asdfasdf<div class='zone_1' style='display:none;'> asdfasdf asdfasdf asfasdf </div>
    </td>
    </tr>
    <tr>
    <td>
     adfasdf<div class='zone_1' style='display:none;'> asdfasdf asdfasdf asdfasdf </div>
    </td>
    </tr>
    </table>

function toggleHist(zone_name){
    //alert(zone_name);
    $('.'+zone_name).toggle();

}

.DisplayNone
{
    display: none;
}


function toggleHist(zone_name){

    $('.'+zone_name).toggleClass('DisplayNone');

}

function toggleHist(zone_name){

    if ($('.'+zone_name).is(":visible"))
         $('.'+zone_name).hide();
    else
         $('.'+zone_name).show();

}