func Init()
  fvar(old, _type)
  switch(typeof(Default))
    case 1:
      _type = 'integer'
      lang(val:int)
    case 7:
      _type = 'real'
      lang(val:real)
    else 
      _type = 'string'
      lang(val:str)
  end
  if(linked(doValue))
    if(isdef(Extern))
      lng.decl_priv_var(val, _type)
      if(isndef(Default))
        old = BLK_CREATE
      end 
    else
      lng.decl_loc_var(val, _type)
      if(isndef(Default))
        old = LOC_HEAD
      end
    end
  end
  if(old)
    old = block.select(old)
    println(val, ' := ', Default, ';')
    sub(val, typeof(Default)) 
    block.select(old)
  end
end

func doValue(_data)
  fvar(dt)
  dt = Data 
  switch(typeof(Default))
    case 1:
      println(val, ' := ', e_int(dt), ';')
    case 7:
      println(val, ' := ', e_real(dt), ';')
    else
      println(val, ' := ', e_str(dt), ';')
  end
  event(onData, val)
end

func Value()
  if(linked(doValue))
    return(val)
  else
    return(Default)
  end
end