Question

I need to add div element to another div, via jquery but it creates two divs

$('div.col-direction').append('<div id="newset"></div>');

Answer 1

this is occurring because the function is binded twice with the handler it can be removed by jQuery.unbind() method.
see Documentation

suppose u are writing on click of button-id “btn”

then instead of

$("#btn").click(function(){
    $('div.col-direction').first().append('<div id="newset"></div>');
});

use

x=$("#btn");
x.unbind('click');
x.click(function(){
    $('div.col-direction').first().append('<div id="newset"></div>');
});