var the_heading = document.getElementById("heading"),
    the_ul = document.getElementById("list"),
    the_button = document.getElementById("button"),
    the_li = document.getElementById("list").getElementsByTagName("li"),
    counter = 1;
/*the_li[0].addEventListener("click" , function(){
the_heading.innerHTML = the_li[0].innerHTML;
});*/
for (let i = 0; i < the_li.length; i++) {
    the_li[i].addEventListener("click" , ahmad) 
    function ahmad ()
    {    the_heading.innerHTML = the_li[i].innerHTML;
    };
};
the_button.onclick = function () 
{ the_ul.innerHTML = the_ul.innerHTML + "<li>New Item "+ counter +"</li>";
    counter ++;
};