script_suggestion.php

<html>

    <script type="text/javascript">

        //document.getElementById("suggestion")

        function getSuggestion(q) {
            var ajax;
            if(window.XMLHttpRequest)//for ie7+, FF, Chrome
                ajax = new XMLHttpRequest();//ajax object
            else
                ajax = new ActiveXObject("Microsoft.XMLHTTP");//for ie6 and previous
            ajax.onreadystatechange = function() {
                if(ajax.status === 200 && ajax.readyState === 4) {
                    //if result are not there then don't display them
                    if(ajax.responseText === "")
                        document.getElementById("suggestion").style.visibility = "hidden";
                    else {
                        document.getElementById("suggestion").style.visibility = "visible";
                        document.getElementById("suggestion").innerHTML = ajax.responseText;
                    }
                }
            };
            ajax.open("GET", "suggestion.php?q=" + q, false);
            ajax.send();
        }
    </script>

</html>