checkout page not completing to step6

We have a working site https://www.vossdirect.ae in opencart Version 1.5.6.4 and has been fully functioning. From today at the check out page the user when select the payment option as credit card, user can't go ahead to next step (step 6) to finish the order.But if cash on delivery is selected the system works fine.

https://www.vossdirect.ae/index.php?rou ... t/checkout

I have live chat with the ix-webhosting and they couldn't give a solution. They concluded like this.
"I got it, I have checked the workaround and there is not much info related to such issue, please note that if cash form works it is not the SSL issue definitely, I can advise you to contact Opencart support for them to check the issue carefully and provide you a proper solution"
can any one help me?

regards,
Binu George

What payment method are you using? Do you get any error in the OpenCart error log? In admin System -> Error Log.

You could also check your web browser's console (usually F12) to see it there are any script errors reported when using credit card.