PayPal standard does not work properly

Hi all, I have enabled PayPal Standard on my website but it doesn't seem to work properly. Upon submitting the order with PayPal as payment method, it just redirects to the PayPal summary, without options to proceed for the payment.

You can try submit an order at my website below to see the problem:

www.cheekylilmummy.com.au

Any help is greatly appreciated!!