Trying to multiply two user inputs PHP - php

Question

I'm trying to make a movie theatre webpage. Very nooby, with almost no PHP and HTML experience. We are learning in school, and we are just using Adobe Dreamweaver to insert stuff like recordsets, bindings, tables etc.
Now I want to make the page where the user can order a ticket, I've created a form, however it only inserts the value of one ticket(obv). I want to make the price to show for 1 ticket, but be stored in MySQL database as price*amount of tickets. I'd be very happy if someone could help me out here:
<form action="<?php echo $editFormAction; ?>" method="post" name="form1" id="form1">
<table align="center">
<tr valign="baseline">
<td nowrap="nowrap" align="right">Pris_kr:</td>
<td><?php echo $row_Recordset1['pris_kr']; ?> pr billett<input type="hidden" value="<?php $row_Recordset1['pris_kr']*$row_antall_billetter;?>"/></td>
</tr>
<tr valign="baseline">
<td nowrap="nowrap" align="right">Personid:</td>
<td><select name="personid">
<?php
do {
?>
<option value="<?php echo $row_Recordset1['personid']?>" ><?php echo $row_Recordset1['epost']?></option>
<?php
} while ($row_Recordset1 = mysql_fetch_assoc($Recordset1));
?>
</select></td>
</tr>
<tr> </tr>
<tr valign="baseline">
<td nowrap="nowrap" align="right">Antall_billetter:</td>
<td><input type="text" name="antall_billetter" value="" size="32" /></td>
</tr>
<tr valign="baseline">
<td nowrap="nowrap" align="right">Rad:</td>
<td><input type="text" name="rad" value="" size="32" /></td>
</tr>
<tr valign="baseline">
<td nowrap="nowrap" align="right">Sete:</td>
<td><input type="text" name="sete" value="" size="32" /></td>
</tr>
<tr valign="baseline">
<td nowrap="nowrap" align="right"> </td>
<td><input type="submit" value="Insert record" /></td>
</tr>
</table>
<input type="hidden" name="bestillingsid" value="" />
<input type="hidden" name="visningsid" value="<?php echo $_GET['visningsid']; ?>" />
<input type="hidden" name="MM_insert" value="form1" />
</form>
again, I'm a newbe and I'm aware of the fault in the code:
<td nowrap="nowrap" align="right">Pris_kr:</td>
<td><?php echo $row_Recordset1['pris_kr']; ?> pr billett<input type="hidden" value="<?php $row_Recordset1['pris_kr']*$row_antall_billetter;?>"/></td>
Am I heading towards something that could help me though?
I'm also using two views here, to get the right time and date, so the url parameters here are "visningsid" and "bestillingsid".
Some translations:
Pris_kr=Price in kr, Antall_billetter=Amount of tickets
The others are not very important I guess.
Thanks in advance
//Sander