jQuery Simple checkbox javascript after styling

checkboxize.css

.e_checkbox,
.e_radiobox {
  position: relative;
  display: inline-block;
  width: 17px;
  height: 17px;
  margin-right: 5px;
}
.e_checkbox input,
.e_radiobox input {
  position: absolute;
  top: 0;
  left: 0;
  opacity: 0;
}
.e_checkbox:before,
.e_radiobox:before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;

  width: 17px;
  height: 17px;

  background: url(../img/spr_radio_check.png) -16px -17px no-repeat;
}
.e_checkbox.checked:before {
  background-position: -16px 0;
}

.e_radiobox {
  width: 16px;
  height: 16px;
}

.e_radiobox:before {
  width: 16px;
  height: 16px;

  background: url(../img/spr_radio_check.png) -16px -16px no-repeat;
}
.e_radiobox.checked:before {
  background-position: -16px 0;
}

checkboxize.js

/* simple checkbox and radio buttons javascript after styling */
$(function() {
	prepareGeneralControls();
});

$("body").on("change", ".e_checkbox > input, .e_radiobox > input", function(e) {
	var i = $(this);
	var obj = $(this).parent();

	if (i.is(":checked")) {
		obj.addClass("checked");
	} else {
		obj.removeClass("checked");
	}
});

function prepareGeneralControls() {	
	$("form input[type='checkbox']").each(function() {
		if (!$(this).parent().is(".e_checkbox")) {
			if ($(this).is(":checked")) {
				$(this).wrap('<span class="e_checkbox checked"></span>');
			} else {
				$(this).wrap('<span class="e_checkbox"></span>');				
			}
		}
	});
	$("form input[type='radio']").each(function() {
		if (!$(this).parent().is(".e_radiobox"))
			$(this).wrap('<span class="e_radiobox"></span>');
	});
}