SMTP Error: Could not connect to SMTP host

I am new to php and working on a project where i am required to send an email(using my gmail id) to the user as soon as he fill up the specified form.
I have tried almost every possible answer that i accessed online but still have not found a solution to it.
Following is the code that i am using-


require_once("PHPMailerclass.phpmailer.php");
$mail= new PHPMailer();
$mail->IsSMTP();
$mail->SMTPAuth=true;
$mail->SMTPSecure="ssl";
$mail->Host="//smtp.gmail.com";
$mail->Port=465;
$mail->Username="xyz@gmail.com";
$mail->Password="*********";


$mail->From="xyz@gmail.com";
$mail->FromName="abc ";
$mail->Subject="Complaint register confirmation";
$mail->MsgHTML("Hello !

Your comlpaint has been registered. We will try to solve it as soon as possible.
");
$mail->AddAddress($b); // $b is the email address of the user
//that is fetched from the form filled up by the user
$mail->IsHTML(true);
$mail->Send();



I am using XAMPP 1.7.4 that has PHP 5.3.5 in it.
I have already changed the settings php.ini i.e.
SMTP=smtp.gmail.com and
smtp_port=465
but could not find "extension=php_openssl.dll". so i added it on my own. I have also overwritten "libeay32.dll" and "ssleay32.dll" in "C:xampp\apache\bin" and restarted services everytime i made changes.
It is still not working and giving following error-
" SMTP Error: Could not connect to SMTP host."

I dont know how to check my smtp is working or not, so haven't checked it yet...
kindly provide me with some help...

Thanks in advance