JQuery :: HTML Function - Automatic Transformation Tag?

I use the html() function for my dialog system, and this function changes the html code...

Example :
$("#jquery_dialog").html(content_html);
alert(content_html);
alert($("#jquery_dialog").html());

The reply is :
Alert:
<form method="post" action="traitement.php">
<select name="select">
[...]
</select><br />
<input type="text" name="text" />
[...]
</form>
<script>
/* jQuery code */
</script>

Alert:
<form method="post" action="traitement.php"></form>
<select name="select">
[...]
</select><br>
<input type="text" name="text" />
[...]

We can see, the code has been modified by html() function...How I can do for insert code without modification??