Easyui checkbox Event onChange not running

Question

i have the isues for the easyui checkbox

this is my code html:

  <input class="easyui-checkbox" type="checkbox" id="ck_target_price" value="on"> Yes/No
  <input style="width:50%;" name="tb_target_price" id="tb_target_price" class="easyui-textbox" disabled="">

and this jquery :

    $('#ck_target_price').onChange(function() {
    if ($("#ck_target_price").is(':checked')) {
        $("#tb_target_price").textbox("disable");
        $("#tb_target_price").textbox("clear");
    } else {
        $("#tb_target_price").textbox("enable");
    }
});

and i want when checkbox change the textbox not disable. but that not working, anyone can help??