Function MyCustomLeave
  push $0 ; abort flag
  push $1 ; page state
  push $2 ; radio button 3 state
  push $3 ; HWND
  push $4 ; text field value
  StrCpy $0 1
  
  # Read the states
  ReadINIStr $1 "licinfodlg.ini" "Settings" "State"
  ReadINIStr $2 "licinfodlg.ini" "Field 3" "State" 
  
  # What was clicked?
  ${If} $1 != 0
    ; get the HWND of the text field
    ReadINIStr $3 "licinfodlg.ini" "Field 4" "HWND"
	; enable/disable based on state of radio button 3
    ${If} $2 = 1 
      ; radio button selected so enable the field
      WriteINIStr "licinfodlg.ini" "Field 4" "Flags" ""
      EnableWindow $3 1
    ${Else}
      ; not selected, so disable field
      WriteINIStr "licinfodlg.ini" "Field 4" "Flags" "DISABLED"
      EnableWindow $3 0
    ${EndIf}
  ${Else}
    ; next button selected
	${If} $2 != 1
	  StrCpy $0 0
	${Else}
	  ReadINIStr $3 "licinfodlg.ini" "Field 4" "State"
      ${If} "$3" == ""
        MessageBox MB_OK "You must enter a value"
      ${Else}
        StrCpy $0 0
      ${EndIf}
	${EndIf}
    
	# now, clean up and exit
	pop $4
	pop $3
	pop $2
	pop $1
	${If} $0 = 1
	  pop $0
	  abort
	${Else}
	  pop $0
	${EndIf}
FunctionEnd