// e. g. <input name="thefile" type="file" size="50" maxlength="500000" accept="image/png,image/jpeg">

static S hfileupload(O... params) {
  if (!containsAtEvenPosition(params, "name"))
    params = arrayPlus(params, "name", "thefile");
  ret hinput("", arrayPlus(params, "type", "file"));
}