Can A system call another system's function (e.g. Enquiry Function) which another application server. does it need web service to handle security issue ?
i.e 1) A System Application function
2) When click a button, it will pop-up B system Payment function (pass the applicaiton no from A to B)
3) After finish B system payment function, then click a button. it will close B system function and back to A System Applicaiton Function.
4) In A System Applicaiton function, I will display a payment receipt No which retrieve from B system.
How to implement above flow? I wish the flow can handle securiy issue... e.g. Only A system can call B system function ...Thanks..