NSIS push, pop and URLEncode Ask Question

I'm trying to encode with URLEncode a strings in NSIS. I'm using a NSIS plugin called URLEncode. The problem is that I try encode 2 vars, but the first encoded var lost the value after I encoded the second var. Push "${AFF_NAME}" Call URLEncode Pop $3 ;at this point the messagebox show the result good. MessageBox MB_OK $3 ReadRegStr $0 HKLM "SOFTWARE\Microsoft\Windows NT\CurrentVersion" "ProductName" Push $0 Call URLEncode Pop $0 ;now after second var encoded the result of first var $3 lost the value MessageBox MB_OK $3 Please Help I'm very new using NSIS and I dont know how do it good. I searching info but without success. Very thanks !