Save textarea content in file with JS and PHP

I have a problem with textarea content which I want to save it in a file. So, an user could write in that textarea some HTML,PHP,JS and/or other tags and it wants to save in a file. First, I declared a variable in JS which takes the textarea value and send via ajax to PHP. The PHP creates a file and insert textarea content in that file.

If I write a simple PHP/HTML/JS code in textarea, the created and saved file doesn't contain anything. It is empty (if I use PHP code in textarea) or sometimes if I write HTML tags in textarea. Look inside my script :

http://pastebin.com/z6CbSNKC

So, what's the problem ? The JS is a problem or PHP code ?

Code from pastebin:

/* HTML code */
Filename with extension : 
<input type="text" placeholder="ex: test.css" id="titlecopypaste" /><br/>
<textarea cols="60" rows="10" placeholder="Insert code here" id="content"></textarea><br/>
<select id="choose">
<option value="public" selected="selected">Public</option>
<option value="private">private</option>
<option value="both">Public si private</option>
</select>
<center><button id="submitcopypaste">Done</button><br/>
<p id="status_create"></p>
</center>




/* Javascript code */
$("#submitcopypaste").click(function()
{
    var fisier=$("#titlecopypaste").val();
    var content=$("#content").text();
    var select=$("#choose").val();
    $.ajax({
        type:"POST",
        url:"include/uploadtxt.php",
        data:"fis="+fisier+"&cont="+content+"&sel="+select,
        success:function(ev)
        {
            $(this).hide();
            $("#status_create").html(ev);
        }
});





/* PHP code */
session_start();
include('Files.php'); //the class created by
include('connect.php');
$status="";
if(isset($_POST['fis'],$_POST['cont'],$_POST['sel']))
    {
        $obj=new Files();
        $file=$_POST['fis'];
        $content开发者_运维知识库=$_POST['cont'];
        $selected=$_POST['sel'];

        switch($selected)
            {
            case "public":{
                $status=$obj->createfile("../diskuser/_public/".$file, $content);break;
            }
            case "private":{
                if(isset($_SESSION['utilizator'],$_SESSION['parola']))
                    {
                $cer=mysql_query("select * from user where nickname='".$_SESSION['user']."' and password='".$_SESSION['parola']."'");
                if($cer)
                    {
                        while($info=mysql_fetch_array($cer))
                            {
                                $status=$obj->createfile("../diskuser/".$info['nickname']."/".$file, $content);break;
                            }
                    }
                else
                    {
                        $status="Connection error!";
                    }
                    }
                else
                    {
                        $status="The session has been expired !";
                    }
                    break;
            }
            case "both":{
                $status=$obj->createfile("../diskuser/_public/".$file, $content);
                $cer=mysql_query("select * from user where nickname='".$_SESSION['user']."' and password='".$_SESSION['parola']."'");
                if($cer)
                    {
                        while($info=mysql_fetch_array($cer))
                            {
                                $status=$obj->createfile("../diskuser/".$info['nickname']."/".$file, $content);break;
                            }
                    }
                else
                    {
                        $status="Database connection error !";
                    }
                    break;
            }
            }
    }
else
    {
        $status="Invalid data !";
    }
    echo $status;
    });

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I think you may need encode the textarea content before send it.