filter search example

gistfile1.php

<?php 
if(isset($_GET['submit'])){

  	extract($_POST);

		if(!empty($subject)){   $extra.= " AND subject = '$subject'"; }	
		if(!empty($id)){        $extra.= " AND id = '$id'"; }	
		if(!empty($FirstName)){ $extra.= " AND FirstName = '$FirstName'"; }	
		if(!empty($LastName)){  $extra.= " AND LastName = '$LastName'"; }	
		if(!empty($address)){   $extra.= " AND address = '$address'"; }	

		$q = mysql_query("SELECT * FROM table WHERE id $extra");
		$r = while($row = mysql_fetch_object($q)){
			//display result here like:
			echo $row->subject;
		}

}
?>