func doCheck(_data)
  fvar(f,e,ms)
  f = '$_FILES[' + FileName + ']'  
  println('$err = 0;')
  if(isset(MaxSize))
    println('if(filesize(', f,'["tmp_name"]) <= ', MaxSize, ') {')
    block.inclvl()
    ms = 1
  else
    ms = 0
  end
  if(isndef(Extensions))
    e = Extensions
    e = replace(e, ',', '", "')
    println('$extlist = array(' + e + ');')
    println('$ex_in = 0;')
    println('foreach ($extlist as $item)')
    println('  if(preg_match("/$item\$/i", ', f, '["name"])) {')
    println('    $ex_in = 1;')
    println('    break;')
    println('  }')
    
    println('if($ex_in) {')
    block.inclvl()
  end
  event(onCheck)
  if(isndef(Extensions)) 
    block.declvl()
    println('}')
    if(linked(onError))
      println('else {')
      block.inclvl()
        println('$err = 2;')
      block.declvl()
      println('}')
    end
  end  
  if(ms)
    block.declvl()
    println('}')
    if(linked(onError))
      println('else {')
      block.inclvl()
        println('$err = 1;')
      block.declvl()
      println('}')
    end
  end
  
  if(linked(onError))
    println('if($err) {')
    block.inclvl()
      event(onError, '$err')
    block.declvl()
    println('}')
  end
end