如何使用codeigniter中的jQuery事件处理复选框

Question

I have created one check box in my view file.

<input type="checkbox" id="country_checkbox" name="country_checkbox" value="0"/>show country

And in javascript file I have written the code to handle the check box, But that code is not at all invoking while changing the checkbox.

 $("#country_checkbox").click(function(){
    alert("this is called");
});

Please help me to solve this