PHP & MySql and Ajax auto-suggest issue - php

Question

I'm using bootstrap for website. I include Ajax, css and PHP to show Auto Suggestions for mp3 search. Everything is working fine but an issue happened. I tried with different way but the issue is still there.
The Issue
When type keyword it show suggestion. (OK)
When you click on keyword from suggestion it works. (OK)
But when we erase keyword and click on anywhere at page then page content reload and shown as u can see in picture.
Url of website is http://www.4songs.pk
Code in header
<script src="http://www.4songs.pk/js/jquery-1.10.2.js"></script>
<script>
$(function(){
$(document).on( 'scroll', function(){
if ($(window).scrollTop() > 100) {
$('.scroll-top-wrapper').addClass('show');
} else {
$('.scroll-top-wrapper').removeClass('show');
}
});
$('.scroll-top-wrapper').on('click', scrollToTop);
});
function scrollToTop() {
verticalOffset = typeof(verticalOffset) != 'undefined' ? verticalOffset : 0;
element = $('body');
offset = element.offset();
offsetTop = offset.top;
$('html, body').animate({scrollTop: offsetTop}, 500, 'linear');
}
</script>
<script type="text/javascript">
var myAjax = ajax();
function ajax() {
var ajax = null;
if (window.XMLHttpRequest) {
try {
ajax = new XMLHttpRequest();
}
catch(e) {}
}
else if (window.ActiveXObject) {
try {
ajax = new ActiveXObject("Msxm12.XMLHTTP");
}
catch (e){
try{
ajax = new ActiveXObject("Microsoft.XMLHTTP");
}
catch (e) {}
}
}
return ajax;
}
function request(str) {
//Don't forget to modify the path according to your theme
myAjax.open("POST", "/suggestions", true);
myAjax.onreadystatechange = result;
myAjax.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
myAjax.setRequestHeader("Content-length", str .length);
myAjax.setRequestHeader("Connection", "close");
myAjax.send("search="+str);
}
function result() {
if (myAjax.readyState == 4) {
var liste = myAjax.responseText;
var cible = document.getElementById('tag_update').innerHTML = liste;
document.getElementById('tag_update').style.display = "block";
}
}
function selected(choice){
var cible = document.getElementById('s');
cible.value = choice;
document.getElementById('tag_update').style.display = "none";
}
</script>
The 2nd issue
When auto suggestions load it also include some empty tags as you can see in picture
I take this picture as doing Inspect Elements
PHP Code are clean
<?php
include('config.php');
if(isset($_POST['search']))
{
$q = $_POST['search'];
$sql_res=mysql_query("SELECT * FROM dump_songs WHERE (song_name LIKE '%$q%') OR (CONCAT(song_name) LIKE '%$q%') LIMIT 10");
while($row=mysql_fetch_array($sql_res))
{?>
<li><a href="javascript:void(0);" onclick="selected(this.innerHTML);"><?=$row['song_name'];?></li>
<?php
}
}?>

Answer 1

In the function request(str) put an if statement to check if str length is greater than zero.
function request(str) {
if(str.length > 0)
{
// Your existing code
}
else
{
document.getElementById('tag_update').innerHTML = '';
}
}
In short words the problem you are describing is happping because the str parameter in the data that you send to /suggestions is empty. The server returns 304 error which causes a redirect to the root page. Your js script places the returned html into the suggestion container. And thats why you are seeing this strange view.
-UPDATE 1-
Added the following code after user request in comments
else
{
document.getElementById('tag_update').innerHTML = '';
}
-UPDATE 2- (16/07/2014)
In order to handle the second issue (after the user updated his question)
Υou forgot to close the a tag in this line of code
<li><a href="javascript:void(0);" onclick="selected(this.innerHTML);"><?=$row['song_name'];?></li>