on my web page i have text area like this

and i suppose to get data in textarea when i alternate the value of select box( or onChange event), so i used ajax function
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.7.2/jquery.min.js"></script>
<script>
function myCall() {
var request = $.ajax({
url: "ajax.php",
type: "GET",
dataType: "html"
});
request.done(function(msg) {
$("#mybox").html(msg);
});
request.fail(function(jqXHR, textStatus) {
alert( "Request failed: " + textStatus );
});
}
</script>
and this is my select box code,
<select name="txtname" id="txtname" onChange="myCall()" >
<option value="0">Select Age:</option>
<option value="100083">100083</option>
<option value="22-26">22-26</option>
<option value="26-30">26-30</option>
<option value="30-34">30-34</option>
</select>
actualy i want to fetch record on the basis of select box value, this function working fine for static value but i am puzzled how to get data from data base.. and my ajax page coding is here..
<?php
$con=mysql_connect("localhost","root","");
if (!$con)
{
die('Could not connect: ' . mysql_error());
}
mysql_select_db("hmc", $con);
$sql="SELECT * FROM news WHERE name = '22-26'";
$result = mysql_query($sql);
?>
<?php
while($row=mysql_fetch_array($result))
{
?>
<tr>
<td>
<?php echo $row['news1'];?></h3></td>
</tr><br /><hr /><br />
<?php
}
?>
</div>
any idea will be appreciated...