把html放到回声中

How to put this code into an echo?

<?php
if ( is_user_logged_in() ) {
    echo 'Welcome, registered user!';
} else {
echo '**Here**';
}
?>

I want to put the code right into the echo, i am newbie in php, i tried changing the " into ' or putting the php strings into the code in another way, i tried everything i was able to search on google and i knew. But nothing worked, i was only able to see a blank page. Could anyone help me understand how to change html and make it fit into the echo? Thank you very much.

<div class="top-bar-login">
    <div id="adv-bar-top">Cosa aspetti ad iscriverti?</div>
    <div class="clear"></div>
<div id="other-bar-top"> 
<a href="/forums">Forum</a>  
<a href="/bacheca">Community</a>
<a href="/help">Help</a>
<a class="lbp-inline-link-2" href="#">Login</a>
<a href="/registrati" class="button-signup-top-bar">Iscriviti</a> 
    </div>
</div>
<div style="display: none;">
<div id="lbp-inline-href-2" style="padding:10px; background: #fff;">
<div id="login-form">
             <h3>Login</h3>
            <fieldset>
                <form action="<?php bloginfo('wpurl') ?>/wp-login.php" method="post">
                    <input type="text" name="log" id="log" required value="Email" onBlur="if(this.value=='')this.value='Email'" onFocus="if(this.value=='Email')this.value='' ">
                    <input type="password" name="pwd" id="pwd" required value="Password" onBlur="if(this.value=='')this.value='Password'" onFocus="if(this.value=='Password')this.value='' ">
                 <input type="submit" name="submit" value="Login">
         <input type="hidden" name="redirect_to" value="<?php echo $_SERVER['REQUEST_URI']; ?>"/>
                    <footer class="clearfix">
                        <p><span class="info">?</span><a href="/wp-login.php?action=lostpassword">Password Dimenticata?</a>
                        </p>
                    </footer>
                </form>
            </fieldset>
        </div>
        <!-- end login-form --> 
</div></div>

PS: I am working with wordpress.

<?php
   if ( is_user_logged_in() ) {
     echo 'Welcome, registered user!';
   } else {
?>
    insert  html here
<?php
   }
?>

PHP allows to write like this this:

  <?php if (condition1){ ?>
      HTML or whatever if condition1 is true
  <?php }elseif (condition2){ ?>
      HTML or whatever if above is false and condition2 is true
  <?php }else{ ?>
      HTML or whatever if all above are false
  <?php } ?>

<?php
if ( is_user_logged_in() ) {
    echo 'Welcome, registered user!';
} else {
?>Insert HTML here!<?
}
?>

It only adds the HTML if is_user_logged_in() == false from the else.