Fetch info without reloading page (when clicking submit button - AJAX?)

[kalender]

Hi!
Coding-gurus, Need some serious help.

If you guys take a look at:
http://83.233.5.191/crurre/index.php

There is a field called "Personnummer". Fill this with:
440611-1890
Then press "Hämta personuppgifter"

It will then fetch/recieve some personal data and fill the correct fields.


But.. as you can see.
The number disappear when the site reloads, but the info fills in which is good at least. So how do I solve this? The number have to stay in the "Personnummer" field without reloading the whole page and still fill in the info.

PHP Code:

<h1>Registrering</h1>
<form action="index.php" method="post">
<div class="input text">
<label for="DataNum">Personnummer</label>
<input type="text" name="personnr" id="data" value=""/>
</div>

<input type="submit" id="GetData" value="Hämta personuppgifter" /> 


Thats how the Personnummer (civic number) field and Hämta personuppgifter (get personal data) looks like.


Hmm hope you guys know how to fix this.. Please write it all simply. Im probably the no1 newbie in here.



Thanks in advance!!

Regards,
K

ps. Would be awesome if You (hope its not too much to request) could post what to add where etc. Since Im a total noob at this.. Thanks. Really appreciate the help!!!

[Fou-Lu]

This has nothing to do with PHP. If you can execute the PHP script with the proper input and receive the proper output, then there is no problem here. Doing it in the background is all client side.
Moving from PHP forum to AJAX forum.