getElementById from select box to text field - database

Question

Im making a selectbox with the values from my DB, and I want to write the ID of the selected item to a textbox.
How can it be done? I have this code..
<form method="POST" action="" id="submitKon">
<fieldset>
<table class="opretTable" border="0">
<tr>
<td width="180" height="30"><label for="valgtkon" class="labelLeft">Vælg konkurrencetype</label></td>
<td><select id="valgtTitel" name="valgtTitel" onchange="run()">
<?php
$virksomhedsID = $_SESSION['virkID'];
$sql = "SELECT * FROM konkurrenceType ORDER BY konkurrenceType.kontypeID";
$result = mysql_query($sql) or die(mysql_error());
echo '<option value="Vælg type">Vælg type</option>';
while($rowSelect = mysql_fetch_assoc($result))
{
echo '<option value="' . $rowSelect['kontypeID'] . '">' . $rowSelect['kontypeTitel'] . '</option>';
}?>
</select>
and..
<script>
function run() {
document.getElementById("valgtID").value = document.getElementById("valgtTitel").value;
}
</script>
I get this
INSERT INTO `mah1233411190550`.`konkurrence` ( `konID` , `virkID` , `konTitel` , `konBeskriv` , `konMaal` , `konMaaltype` , `konStart` , `konSlut`, `kontypeID`, `holdID` ) VALUES (NULL , '1', '1', 'cykle', '500', 'km', '2013-01-01', '2018-05-03', '1', '' );
So konTitel is the same as kontypeID, why is that?

Answer 1

You can do something like:
var valgtTitel = document.getElementById("valgtTitel");
document.getElementById("valgtID").value = valgtTitel.options[valgtTitel.selectedIndex].value;
Here's fiddle: http://jsfiddle.net/viralpatel/JYHLM/
Edit:
Perhaps you might want to save the title (apart from ID) in some other textbox and retrieve it from request:
var valgtTitel = document.getElementById("valgtTitel");
document.getElementById("valgtTitle").value = valgtTitel.options[valgtTitel.selectedIndex].innerHTML;
Note how we used innerHTML instead of value to get the title.

Answer 2

So something like this??
<tr>
<td width="180" height="30"><label for="valgtkon" class="labelLeft">Vælg konkurrencetype</label></td>
<td><select id="select" name="select" onchange="run()">
<?php
$virksomhedsID = $_SESSION['virkID'];
$sql = "SELECT * FROM konkurrenceType ORDER BY konkurrenceType.kontypeID";
$result = mysql_query($sql) or die(mysql_error());
echo '<option value="Vælg type">Vælg type</option>';
while($rowSelect = mysql_fetch_assoc($result))
{
$kontypeID = $rowSelect['kontypeID'];
$kontypeTitel = $rowSelect['kontypeTitel'];
echo '<option value="' . $kontypeID . '">' . $kontypeTitel . '</option>';
}?>
</select></td>
<script>
function run() {
var select = document.getElementById("select");
document.getElementById("valgtID").value = valgtTitel.options[select.selectedIndex].innerHTML; //how to make this right?
document.getElementById("valgtTitel").value = valgtTitel.options[select.selectedIndex].innerHTML; //how to make this right?
}
</script>
<td><input type="text" name="valgtID" id="valgtID"/><input type="text" name="valgtTitel" id="valgtTitel"/></td>
</tr>