Question

The problem is this.I want to save every message in MySQL DB and I try to do this making this javascript function:

function doWork(str)
{
var xmlhttp;
if (window.XMLHttpRequest)
  {// Използваните браузъри
  xmlhttp=new XMLHttpRequest();
  }
else
  {// Кой ли ползва тези версии..
  xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
  }
    xmlhttp.open("GET","newmsg.php?q="+str,true);
    xmlhttp.send();
}

Then the text field :

  <div id="sender">
     Your message: <input type="text" name="msg" size="30" id="msg" />
     <button onclick="doWork(this.msg);">Send</button>
  </div>

And finally the php file:

$q=$_GET["q"];
  (str)$q;
    $db_connect = mysql_connect('localhost', 'root', 'diamond');
    if(!$db_connect)
        {
         die('Не може да се осъществи връзка с базата данни' . mysql_error());
        }
mysql_select_db("chat", $db_connect);
$sql = "INSERT INTO messages (user_id, time, text) VALUES ('1','1234','$q')";
mysql_query($sql);
mysql_close($db_connect);

And what actually happen is that the user_id and time fields are filled properly, but the ‘text’ filed says “undefined”.
What does it mean and how can I fix the problem(s)?
Thanks
Leron

Answer 1

I believe the issue is in your reference to the input text field. Try this instead:

<div id="sender">
   Your message: <input type="text" name="msg" size="30" id="msg" />
   <button onclick="doWork(document.getElementById('msg').value);">Send</button>
</div>

When you use the following, ‘this’ refers to the button element, so don’t do the following.

<button onclick="doWork(this.msg);">Send</button>