function $(id) {
     return document.getElementById(id);
}

function sprawdz_dane() {
...
}

function do_suggest() {
    string = $('towar').value;
    pole_div = $('suggestions');
    if(!string)
        pole_div.style.display='none';
    else {
            var zapytanie = "http://localhost/Remament/czy_istnieje.php?wysw="+string;
            advAJAX.get({
                url : zapytanie,
                onSuccess : function(obj) {
                    if(obj.responseText != " ") {
                        pole_div.innerHTML = ' ';
                        var str_wyniki = obj.responseText;
                        var tablica_wynikow = str_wyniki.split("<>");
                        for(var i = 0; i < tablica_wynikow.length; i++) {
                            var result = document.createElement('span');
                            result.innerHTML = tablica_wynikow[i];
                            pole_div.style.display = 'block';
                            pole_div.appendChild(result);
                        }
                    }
                    else pole_div.style.display = 'none';
                }
            });
    }
}

[PHP] pobierz, plaintext 
<?php
...
if($_GET['wysw']) {
	$string = mysql_escape_string($_GET['wysw']);
	$sql = mysql_query("SELECT `nazwa` FROM towary WHERE nazwa LIKE '$string%'", $lnk);
	if(mysql_num_rows($sql) == 0) exit;
	while($row = mysql_fetch_array($sql))
		echo $row[0] .'<>';
}
?>
[PHP] pobierz, plaintext