Chained dropdown option not pulling previous values through in to query - php

Question

I have found a example of chained dropdown boxes, however i am struggling to ensure that the 3rd box uses both the previous boxes in showing the required results.
The boxes are intended to show the following,
DROP DOWN BOX 1 = Select a sector
DROP DOWN BOX 2 = Select a Level
DROP DOWN BOX 3 = Select a Qualification
On the last SQL query i have shown a $HELP, i think this is where im having my problems, i think it is loosing the previously stored value in dropdown box 1 when dropdown box 2 is selected.
<?php
//**************************************
// Page load dropdown results //
//**************************************
function getTierOne()
{
$result = mysql_query("SELECT DISTINCT SSA1Text FROM qualifications ORDER BY SSA1Text ASC")
or die(mysql_error());
while($tier = mysql_fetch_array( $result ))
{
echo '<option value="'.$tier['SSA1Text'].'">'.$tier['SSA1Text'].'</option>';
}
}
//**************************************
// First selection results //
//**************************************
if($_GET['func'] == "drop_1" && isset($_GET['func'])) {
drop_1($_GET['drop_var']);
}
function drop_1($drop_var)
{
include_once('db.php');
$result = mysql_query("SELECT DISTINCT Level FROM qualifications WHERE SSA1Text='$drop_var' ORDER BY Level ASC")
or die(mysql_error());
echo '<select name="drop_2" id="drop_2">
<option value=" " disabled="disabled" selected="selected">Choose one</option>';
while($drop_2 = mysql_fetch_array( $result ))
{
echo '<option value="'.$drop_2['Level'].'">'.$drop_2['Level'].'</option>';
}
echo '</select>';
echo "<script type=\"text/javascript\">
$('#wait_2').hide();
$('#drop_2').change(function(){
$('#wait_2').show();
$('#result_2').hide();
$.get(\"func.php\", {
func: \"drop_2\",
drop_var: $('#drop_2').val()
}, function(response){
$('#result_2').fadeOut();
setTimeout(\"finishAjax_tier_three('result_2', '\"+escape(response)+\"')\", 400);
});
return false;
});
</script>";
}
{//**************************************
// Second selection results //
//**************************************
if($_GET['func'] == "drop_2" && isset($_GET['func'])) {
drop_2($_GET['drop_var']);
}
function drop_2($drop_var)
{
include_once('db.php');
$result = mysql_query("SELECT * FROM qualifications WHERE Level='$drop_var' AND SSA1Text='$HELP'")
or die(mysql_error());
echo '<select name="drop_3" id="drop_3">
<option value=" " disabled="disabled" selected="selected">Choose one</option>';
while($drop_3 = mysql_fetch_array( $result ))
{
echo '<option value="'.$drop_3['Title'].'">'.$drop_3['Title'].'</option>';
}
echo '</select> ';
echo '<input type="submit" name="submit" value="Submit" />';
}
?>
Any help would be much appreciated.

Answer 1

You could pass both select variables to drop_2 function?
function drop_2($drop_var1, $drop_var2 == null) {
if ($drop_var2 !== null) {
$sqlSnipet = " AND SSA1Text='$drop_var2'"
}
$result =
mysql_query(
"SELECT *
FROM qualifications
WHERE Level='$drop_var' " .
$sqlSnipet
) or die(mysql_error());
}