Jquery form field value

How can I the HTML string <br> from this HTML FORM pass to the DIV using Jquery?

HTML FORM is:

<form action="" id="submit_wall" name="submit_wall" method="post">
<textarea cols="50" rows="5" id="message_wall"></textarea>
<button type="submit" id="fst" class="cfst">send</button>
</form>

 <div id="wall"></div>
 <div class="msg"></div>

Jquery code:

$(document).ready(function(){    
$("form#submit_wall").submit(function() {
var message_wall = $(开发者_如何学C'#message_wall').attr('value');

$("div#wall").append('<div class=msg>'+ message_wall +'</div>');
return false; 
});
});

I'm trying using .html() but I keep getting error message.

Here is an example from learningjquery.com

$(document).ready(function() {
  $('#comment').one('focus',function() {
 $('#comment').parent().after('<div id="preview-box"><div class="comment-by">Live Comment Preview</div><div id="live-preview"></div></div>');
  });
  var $comment = ''; // that's two single quotation-marks at the end
  $('#comment').keyup(function() {
 $comment = $(this).val();
 $comment = $comment.replace(/\n/g, "<br />").replace(/\n\n+/g, '<br /><br />').replace(/(<\/?)script/g,"$1noscript");
 $('#live-preview').html( $comment );
  });
});

Which is very close of what you are trying to do.

First, as durilai commented, there is no div with an ID of wall, which means that even if your submit handler is working, append isn't going to append since there's nothing to append to.

Second, even though you said action="" on the form, the form will still submit and cause what looks like a page reload because you are not preventing the default action in your submit handler. One quick fix is to add return false; as the last line of the handler. Another fix is to rewrite it like:

$("form#submit_wall").submit(function(event) {
    event.preventDefault();

    $("div#wall").append("<div class='msg'>"+ $("#message_wall").val() + "</div>");
});