[jQuery] Username Checking

[jQuery] Username Checking


I have the following code.
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://
www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
        <html xmlns="http://www.w3.org/1999/xhtml">
        <head>
            <meta http-equiv="Content-Type" content="text/html;
charset=ISO-8859-1" />
            <title>Labs</title>
            <link rel="stylesheet" type="text/css" href="../css/main.css" />
            <link rel="stylesheet" type="text/css" href="../css/blog.css" />
            <link rel="stylesheet" type="text/css" href="../css/admin.css" />
            <script type="text/javascript" src="../ajax/jquery/jquery-1.1.4.js"