ช่วยดูหน่อยครับ เช็คค่า textbox แสดงรูปถูกด้านข้าง ทำไมมันไม่โชว์ครับ

<?php
@mysql_connect( "localhost" ,  "root" , "1234" ) or die(mysql_error());
mysql_query( "CREATE  DATABASE  ajaxuserchecker;" );
mysql_select_db( "ajaxuserchecker" );

$sql="CREATE TABLE tblmember (
	id SMALLINT Not Null AUTO_INCREMENT PRIMARY KEY,
	loginname VARCHAR(15) Not Null,
	password VARCHAR(15) Not Null,
	UNIQUE(loginname));";
	
	$result=mysql_query($sql);
	if (!$result) {
		echo "ไม่สามารถสร้างตาราง tblmember ได้";
	} else {
		echo "สร้างตาราง tblmember เสร็จเรียบร้อย";
	}

$sql = "INSERT INTO  tblmember VALUES ( '', 'visawut', '1111' )";
@mysql_query($sql) or die(mysql_error());

$sql = "INSERT INTO  tblmember VALUES ( '', 'akeanan', '2222' )";
@mysql_query($sql) or die(mysql_error());

$sql = "INSERT INTO  tblmember VALUES ( '', 'surachai', '3333' )";
@mysql_query($sql) or die(mysql_error());

?>

<script type="text/javascript" src="veriflogin.js"></script>

<form name="form1" id="form1">
  <table width="450" border="0" align="center">
    <tr>
      <td colspan="2"><strong>Member Register</strong></td>
    </tr>
    <tr>
      <td>Username :</td>
      <td><input name="txtUsername" type="text" id="txtUsername" size="12" onKeyUp="verifLogin(this.value)"> <span id="msg1"></span><br /><span id="msg2"></span> </td>
    </tr>
    <tr>
      <td>Password :</td>
      <td><input name="txtPassword" type="text" id="txtPassword" size="12"></td>
    </tr>
    <tr>
      <td>&nbsp;</td>
      <td><input type="submit" name="submit" id="submit" value="Login"></td>
    </tr>
  </table>
</form>

<?php
$objConnect = mysql_connect( "localhost" , "root" , "1234" ) or die(mysql_error());
$objDB = mysql_select_db( "ajaxuserchecker" ) or die ( "ไม่สามารถเชื่อมต่อฐานข้อมูลได้" );
mysql_query( "SET NAMES utf8" , $objConnect );
?>

<?php
require("config.php");

$strTxt = $_GET['username'];

$result = mysql_query( "SELECT loginname FROM tblmember WHERE loginname = '$strTxt' " ); 

if (trim($strTxt) == "" ) {
    echo "<img src='image/icon_wrong.gif'>";
    exit();
} else {

    if (mysql_num_rows($result) >= 1 ) {
        echo "<img src=\"image/icon_wrong.gif\" width=\"20\" height=\"20\" />";Code (JavaScript)


    } else {
        echo "<img src=\"image/icon_correct.gif\" width=\"20\" height=\"20\" />";
    }	
}
?>

function writediv(texte) { 
    document.getElementById('msg2').innerHTML = texte; 
} 
	 
function verifLogin(txt) { 
    if ( txt != '' ) { 
        if ( txt.length < 5 )  {
            writediv('<span style="color:#cc0000">ควรมีอย่างน้อย 5 ตัวอักษร !</span>');    
        } elseif ( txt.length > 12 )  {
            writediv('<span style="color:#cc0000">ไม่ควรเกิน 15 ตัวอักษร !</span>'); 
        } elseif ( getFile('veriflogin.php?username=' + escape(txt)) )  { 
            document.getElementById('msg1').innerHTML = xhr_object.responseText;
        } 
    } 
}

function getFile(url) { 
    if ( window.XMLHttpRequest ) {
        xhr_object = new XMLHttpRequest(); 
    } else if ( window.ActiveXObject ) {
        xhr_object = new ActiveXObject( "Microsoft.XMLHTTP" ); 
    } else {
    return(false); 
 }

 xhr_object.open( "GET" , url, false ); 
 xhr_object.send(null); 

 if (xhr_object.readyState == 4) {
    return(xhr_object.responseText); 
 } else {
    return(false); 
 } 
}