<form name='search' method='post'>
    Keresés erre: <input type='text' name='find' />
    <input type='hidden' name='searching' value='yes' />
    <input type='submit' name='search' value='Keres' />
 </form>
<?php



    if ($_REQUEST["searching"] == 'yes') { echo '<h3>Találatok:</h3>' . "<hr>"; }
    //if ($_POST['find']    == "") { echo "<h5>Nem adott meg keresési feltételt</h5>"; }
    $find=$_REQUEST["find"];

$db = mysql_connect('localhost','...','...') or die(mysql_error());
$mydb = mysql_select_db('...');
$sql = "...";
$result=mysql_query($sql);
echo "<table border='1'>";
while ($row = mysql_fetch_array($result))
{
...
}