Simple Form Validation Using JQuery

///////////////////////////////////////////////////////////////////////////////////////////////////
//// index.php
///////////////////////////////////////////////////////////////////////////////////////////////////
<?php
session_start();
include("connect.php");
if(isset($_COOKIE['username'])) {
$username =$_COOKIE['username'];
}
else {
$username = '';
}
if(isset($_COOKIE['password'])) {
$password =$_COOKIE['password'];
}
else {
$password ='';
}
if(isset($_COOKIE['rememberme'])) {
$rememberme =$_COOKIE['rememberme'];
}
else {
$rememberme ='';
}
if(isset($_REQUEST['action'])) {
$loginSql = "SELECT * FROM login WHERE login_name='".mysql_real_escape_string($_REQUEST['username'])."' AND
login_password='".mysql_real_escape_string($_REQUEST['password'])."'";

$loginquery = mysql_query($loginSql) or die(mysql_error()) ;
if(mysql_num_rows($loginquery)<=0){
$msg = '<font color=#FF0000>Invalid login</font>';;
}
else {
if(isset($_REQUEST['rememberme'])) {
setcookie("username",$_REQUEST['username'],time()*3600); //it is in sec
setcookie("password",$_REQUEST['password'],time()*3600);
setcookie("rememberme",$_REQUEST['rememberme'],time()*3600);//// creates a cookie of name rememberme for 1 hour/////
}
else {
setcookie('username','');  //means you are deleting a cookie
setcookie('password','');
setcookie('rememberme','');/////sysntax for deleting a cookie////
}
$loginArr = mysql_fetch_array($loginquery);
$userId = $loginArr['login_id'];
$_SESSION['usrerid'] = $userId;
$_SESSION['username'] = $loginArr['login_name'];
header("location:index.php");
exit();
}
}
if(isset($_REQUEST['logout'])) {
unset($_SESSION['usrerid']) ;
unset($_SESSION['username']) ;
header("location:login.php");
}



?>
<script src="jquery-1.10.1.js"></script>
<script>
    $(document).ready(function() {
$('#login').attr('onsubmit','return chkValidate()') ;
//$('#usernamr').attr('readonly','readonly')
$('#login').attr('onsubmit','return chkValidate()');

});
function chkValidate() {
var usernamr = $('#usernamr').val();
var password = $('#password').val();
var err = 0;
var msg = '';
if(usernamr == '') {
err++;
msg = msg+'<li>Enter Uename</li>';
}
if(password == '') {
err++;
msg = msg+'<li>Enter password</li>';
}
if(err>0){
$('#msg').html(msg);
if(document.getElementById("errormsg").style.display == "none") {
$("#errormsg").toggle();
}
return false;
}
else {
return true;
}
}


</script>







<h3 align="center">Enter Your login details</h3>
<form method="POST" action="#" id="login" >
<table align="center">
<tr><td>Username</td><td><input type="text" name="username" id="usernamr" value="<?php echo $username ;?>"></td></tr>
<tr><td>Password</td><td><input type="password" name="password" id="password" value="<?php echo $password ;?>"></td></tr>
<tr><td>Remember Me</td><td><input type="checkbox" name="rememberme" id="rememberme" value="Y" <?php if($rememberme == 'Y') { ?> checked="checked"<?php } ?>></td></tr>
<tr><td colspan="2"><input type="submit" name="submit" value="Submit" id="formlogin">
<input type="hidden" name="action" value="Trans">
<?php
if(isset($msg)) {
echo $msg ;
}
?>
<span id="errormsg" style="display:none">

<table align="center" cellpadding="1" cellspacing="0" width="75%" border="2" style="border:thick" bgcolor="#999999">
<tr>
<td><span id="msg" style="color:#ff0000;"></td>


</tr>
</table>
</span>
</span>



</td></tr>
</table>
</form>
///////////////////////////////////////////////////////////////////////////////////////////////////
//// End index.php
///////////////////////////////////////////////////////////////////////////////////////////////////
///////////////////////////////////////////////////////////////////////////////////////////////////
//// connect.php
///////////////////////////////////////////////////////////////////////////////////////////////////
<?php

class connect{
   function dbconnect(){
   $con=mysql_connect($this->hostname,$this->username,$this->password);
   mysql_select_db($this->dbname,$con) or die(mysql_error());
      }



}
  $obj=new connect;
  $obj->hostname="localhost";
  $obj->username="root";
  $obj->password="";
  $obj->dbname="pmsd";
  $obj->dbconnect();



?>
///////////////////////////////////////////////////////////////////////////////////////////////////
//// End connect.php
///////////////////////////////////////////////////////////////////////////////////////////////////