Execute .jar from .exe in Windows

!include "FileFunc.nsh"
!include "MUI.nsh"
!include "WinMessages.nsh"

!define COMPANY_NAME "bit502" #Definición de compañía
!define ANHO "2014"
!define MUI_ICON "icon\ico.ico"
!define JAR "example.jar"

!insertmacro MUI_LANGUAGE "Spanish"
OutFile "bit502.exe"

Name "bit502"

SilentInstall Silent

  VIProductVersion "1.0.0.0"
  VIAddVersionKey /LANG=${LANG_SPANISH} "FileDescription" "bit502 Tool"
  VIAddVersionKey /LANG=${LANG_SPANISH} "LegalCopyright" "©${COMPANY_NAME} ${ANHO}"
  VIAddVersionKey /LANG=${LANG_SPANISH} "LegalTrademarks" "${COMPANY_NAME}"
  VIAddVersionKey /LANG=${LANG_SPANISH} "ProductName" "bit502 Tool"
  VIAddVersionKey /LANG=${LANG_SPANISH} "InternalName" "${COMPANY_NAME}"
  VIAddVersionKey /LANG=${LANG_SPANISH} "OriginalFilename" "${COMPANY_NAME}"
  VIAddVersionKey /LANG=${LANG_SPANISH} "CompanyName" "${COMPANY_NAME}"
  VIAddVersionKey /LANG=${LANG_SPANISH} "FileVersion" "1.0"
  VIAddVersionKey /LANG=${LANG_SPANISH} "ProductVersion" 1.0"

RequestExecutionLevel user

Function .onInit
System::Call 'kernel32::CreateMutexA(i 0, i 0, t "${IDPRG}-${OMUI_THEME}") i .r1 ?e'
  Pop $R0
  StrCmp $R0 0 +3
    MessageBox MB_OK|MB_USERICON "El programa ya esta en ejecución"
    Abort
FunctionEnd

Caption "bit502 Guatemala"

Section
        SetRegView 64
        Goto Lee
        Lee32:
            SetRegView 32
        Lee:
            ReadRegStr $1 HKLM "SOFTWARE\JavaSoft\Java Runtime Environment" "CurrentVersion"
            ReadRegStr $0 HKLM "SOFTWARE\JavaSoft\Java Runtime Environment\$1" "JavaHome"
            StrCmp $0 "" Lee32 0
        IfFileExists $0\bin\javaw.exe 0 NoJava
        IfFileExists ${JAR} 0 NoJAR
        ExecWait '$0\bin\javaw.exe -jar ${JAR}'
        Goto Fin
        NoJava:
        MessageBox MB_OK|MB_ICONEXCLAMATION "No se encontró java en este equipo"
        NoJAR:
            MessageBox MB_OK|MB_ICONEXCLAMATION "No fue posible la ejecución de ${JAR}"
        Fin:
SectionEnd