Paid Subscriptions, do something after payment..
 

So I currently have a board setup with one subscription. I am wanting to make the subscription system send data once a successful payment has been made.

Before this would happen, it would need to check to see if the user has a populated "steam_code" column in the "users" table.(e.g STEAM_0:0:33414899). If the condition isn't met, then relay a vbulletin error page, asking the user to link their account.

Then it would allow the user to purchase this subscription, and upon completion, it would send a link to a script I will soon construct, which would post data or put it in the url.

Given that we post or send two variables, the user's steam ID and subscription ID(I will be able to differentiate what they bought).

An example would be From there I could finish off the work and make it more convenient for my users to simply subscribe from the forums and make it automated, as well as helping me out from having to manually do it. I can figure out the rest of the work on the second php script, but I am not very familiar with Vbulletin's conditional statements and inner workings.

Thank you for reading, and any help would be greatly appreciated, I hope this comes from pen and paper to real time, as well as helping other communities that may find this useful.