I have integrated the PayPal standard payment code block on to my web page and it is working well. The code block has only one parameter 'amt'. Now I want to add another parameter 'invcid'. However, after I added invoice number as the second parameter onto a test payment page, although the page is displayed as expected but both the PayPal and credit card payment buttons are disabled. I do not know why and how to get it working. It is very interesting that if I just make a minor change on the Invoice Number field on the following test page (say, delete the last ‘3’ and then put back), then both the PayPal payment button and the credit card payment button become activated. Could you please advise how to solve the problem?
