How to make facebook comment box width 100%?

Question

i am using this code to put a facebook comment box to my page,

Answer 1

setTimeout(function run() {
    if ($('.fb-comments span:first-child, .fb-comments span iframe').length == 0)
        setTimeout(run, 1000);
    else
        $('.fb-comments span:first-child, .fb-comments span iframe')[1].style.width = "100%";
}, 1000);