[wirehopper]

Another option:

PHP Code:

/* Default page - either the same page, or an error page */

$sPage='default.php';

/* Ensure both ids are set.  It's okay if they are set but empty */

if (isset($_POST['id1']) && isset($_POST['id2']))

{

  $aPageMap=array('101'=>'page1.php',

                                '102'=>'page2.php',

                                '103'=>'page3.php',

                                '201'=>'page4.php',

                                '202'=>'page5.php',

                                '203'=>'page6.php',

                                '301'=>'page7.php',

                                '302'=>'page8.php',

                                '303'=>'page9.php');

  /* Create the array index - it's okay if it is not valid */

  $iPageIndex=$_POST['id1'].$_POST['id2'];

  /* Check to see if the array index is valid, if so, use it */

  if (array_key_exists($iPageIndex,$aPageMap))

    $sPage=$aPageMap[$iPageIndex];

}

/* Go to the page */

header('location: '.$sPage); 

This could also be done in javascript, like so:

HTML Code:

<script type="text/javascript">
function go()
{
  var o1=document.getElementById('id1');
  var o2=document.getElementById('id2');
  var i=0;l=o1.options.length;
  for (i=0;i<l;i++)
  if (o1.options[i].selected)
  {
    m=o2.options.length;
    for (j=0;j<m;j++)
      if (o2.options[j].selected)
        location.href=o1.options[i].value+o2.options[j].value;
  }
}
</script>

<!-- Be sure to give the <select> tags ids -->
<select name="id1" id="id1">

...

<select name="id2" id="id2">

...

<button onclick="go()">Go</button>

Not tested.