Auto-save textarea every so many seconds - php

Question

I need help with "auto-saving" a textarea. Basically, whenever a user is typing in the textarea, I would like to save a "draft" in our database. So for example, a user is typing a blog post. Every 15 seconds I would like for the script to update the database with all text input that was typed into the textarea.
I would like for this to be accomplished thru jQuery/Ajax but I cannot seem to finding anything that is meeting my needs.
Any help on this matter is greatly appreciated!
UPDATE:
Here is my PHP code:
<?php
$q=$_GET["q"];
$answer=$_GET["a"];
//Connect to the database
require_once('mysql_connect.php') ;
$sql="UPDATE english_backup SET q".$q."='".$answer."' WHERE student_id = {$_COOKIE['student']} LIMIT 1";
$result = mysqli_query($dbc, $sql);
?>
Here is my javascript code:
<script type="text/javascript">
function showUser(str, answer)
{
if (str=="")
{
document.getElementById("txtHint").innerHTML="";
return;
}
if (window.XMLHttpRequest)
{// code for IE7+, Firefox, Chrome, Opera, Safari
xmlhttp=new XMLHttpRequest();
}
else
{// code for IE6, IE5
xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
}
xmlhttp.onreadystatechange=function()
{
if (xmlhttp.readyState==4 && xmlhttp.status==200)
{
document.getElementById("txtHint").innerHTML=xmlhttp.responseText;
}
}
xmlhttp.open("GET","getuser_english.php?q="+str+"&a="+answer,true);
xmlhttp.send();
}
</script>

Answer 1

function saveText() {
var text = $("#myTextArea").val();
// ajax call to save the text variable
// call this function again in 15 seconds
setTimeout(saveText, 15000);
}();

Answer 2

I think you want something like ajax... I'm using ajax jQuery so you will need jQuery Library for it to work. Download it. You can find tutorials on the documentation tab of the website.
//in your javascript file or part
$("textarea#myTextArea").bind("keydown", function() {
myAjaxFunction(this.value) //the same as myAjaxFunction($("textarea#myTextArea").val())
});
function myAjaxFunction(value) {
$.ajax({
url: "yoururl.php",
type: "POST",
data: "textareaname=" + value,
success: function(data) {
if (!data) {
alert("unable to save file!");
}
}
});
}
//in your php part
$text = $_POST["textareaname"];
//$user_id is the id of the person typing
$sql = "UPDATE draft set text='".$text."' where user_id='".$user_id."'"; //Try another type of query not like this. This is only an example
mysql_query($sql);
if (mysql_affected_rows()==1) {
echo true;
} else echo false;
Hey everyone I'm still having a problem please see here https://stackoverflow.com/questions/10050785/php-parse-html-using-querypath-to-plain-html-characters-like-facebook-twitter