Creat Multiple Dynamic Drop-down List in PHP/Javascript

<link href="mainCSS.css" rel="stylesheet" type="text/css">
      <form name="myform" method="post" action=""> 
      <table width="100%"  border="0" cellpadding="0" cellspacing="0">
      <tr class="maincss">
<?php
 
	$tagList = 'word1, word1, word3, word4, word5, word6'; //this is the input string to be parsed to several words
	
if (isset($tagList))
{
	// Step 1: parse the string
	$tags = array(); //array to store each tag
	
	if (is_int(strpos($tagList, ',')))
	{	
		$tags = explode(',', $tagList); // Multiple tags
	}
	else 
	{
		$tags[] = $tagList; // Just one tag
	}
	//Step 2: connect to the database to get the corresponding list of values
	$con = mysql_connect('localhost','username','pasword')
    				or die("CAN NOT CONNECT TO SERVER");
    $sel = mysql_select_db('database',$con)
    				or die("CAN NOT SELECT DATABASE");
					
	foreach ($tags as $index => $nextTag) 
	{
		$nextTag = ltrim(rtrim($nextTag));
    	print"<tr class=\"maincss\">";
     	print"<td>&nbsp;</td>";
     	print"<td height=\"15\" nowrap class=\"maincss\">Tag:</td>";
		print"<td nowrap class=\"maincss\">".$nextTag."</td>"; //prints each tag
		print"<td>&nbsp;</td>";
      	print"<td nowrap class=\"maincss\">";
     	 
		$q_select_count = mysql_query("SELECT int_resource_id, str_resource_name FROM `resources` where str_resource_name = '". $nextTag ."'");	
 
			$retunedMatchingTags = array();
			$indexRetunedMatchingTags = 0;
			while ($row = mysql_fetch_array($q_select_count)) 
			{
				$retunedMatchingTags[$indexRetunedMatchingTags][0] = $row["int_resource_id"]; 				
				$retunedMatchingTags[$indexRetunedMatchingTags][1] = $row["str_resource_name"]; 
				$indexRetunedMatchingTags = $indexRetunedMatchingTags + 1;
			}
			
			if ($indexRetunedMatchingTags > 0) //checks if there were corresponding words in the database
			{
				print"This word matched the following words in our database: ";
				print"<select onChange=\"resubmit()\">";
				foreach( $retunedMatchingTags as $returnedIDs => $returnedRow)
				{
					print "<option id=\"" . $retunedMatchingTags[$returnedIDs][0] . "\" name=\"" . $retunedMatchingTags[$returnedIDs][1] . "\" value =\"" . $retunedMatchingTags[$returnedIDs][1] . "\">". $returnedIDs.") ".$retunedMatchingTags[$returnedIDs][1]."</option>";
				}
				print "";
				print"</select>";
				
		    }
			else // no matching words were found
			{
				print "This word didn't match any other word in our database";
			}
		print "</td>";		
	 	
	}
	
	print"<td nowrap class=\"maincss\">";
	print "</td>";
 
 
	// here is where i want to add Step there and add a second drop-down-list corresponding to what was chosen
 
	print"</tr>";
 
 
	
mysql_close($con);
 
}