How to call div tag in javascript function

<div id="cd-signup">
        <!-- sign up form -->
        <form name="joinform" class="cd-form" id="joinform" method="post">
            <input type="hidden" name="act" value="register">
            <div class="modal-dialog">
                <div class="modal-content">
                    <div class="modal-header">
                  .....
                  ....

function testAPI() {

    console.log('Welcome!  Fetching your information.... ');
    FB.api('/me?fields=id,name,email,permissions', function(response) {
        console.log('Successfulllll login for: ' + response.name);
        name=response.name;
        alert(name+"===="+response.email);
        //here I want to call that Div tag 
    });
}

---

Now I'm using facebook api

and I want to call that sign up form when I finish facebook login

Please help me...