HI. I have multiple webpages. So I have a common external js file. And I have added this js file to every page. I have multiple check boxes in every page. And I have written the click event in the external, common js file. But I wonder how the js file should be? Currently I have written like this. $(document).ready(function() { $(".chk").click(function() { alert("hi"); }); }); But whenever I click a checkbox the click event is fired twice. it should be once. I dont know where is the error, is there any error in writing the js file? please comment.