计数+ / - 用于复选框单击并取消选中

Question

When a user clicks the checkbox the counter #counter +1, thats fine, but when he unchecks it does not -1 for the same checkbox. I want to +1 when they click a particular checkbox and when unchecking -1.

--JS--

$('.CheckBox').toggle(function(){
    $('#Counter').html('( '+i+' Selected )');
    i++;
}, function() {

    $('#Counter').html('( '+i+' Selected )');
    i--;
});

---PHP---

do { ?>

<div style="position:relative; width:100%; height:20px; background-color:#FF5300;" class="CheckBox" id="<?php echo $row_EX['x1']; ?>">

<input type="checkbox" name="<?php echo $row_EX['x2']; ?>" value="<?php echo $row_EX['x3']; ?>" style="cursor:pointer; ">

<span style="position:relative; top:-2px; font-family:arial; color:#000; font-size:12px;"><?php echo $row_EX['lx4']; ?></span>

</div>

<div style="height:1px; width:1px;"></div>
<?php } while ($row_EX = mysql_fetch_assoc($EY)); ?>    

<span style="position:relative; left:10px; top:6px; font-family:arial; font-size:16px;" id="counter">(0 Selected)</span>

Answer 1

$('.CheckBox').change(function() {
  if (this.checked) {
    i++;
  } else {
    i--;
  }
  $('#Counter').html('( '+i+' Selected )');
});

Make sure you initialise var i = 0; when the page loads.