Calling the RFC from other system.

Hi Everybody.

I have two systems.One is ECC and other is SAP R/3.

I have created one RFC in SAP R/3 system and I am calling this

RFC fom ECC system.On click of one button,I have to show some

fields from the RFC onto the screen of WDA .

How can I achieve it ? Is there any code for that or some link

available for that.

Thanks In Advance.