How to read formControlRange Value after pressing a button

[newsanti]

Please add the name attribute to the input field, the same as ID, example:

<input id="formControlRange" name="formControlRange">

Missing input Name. Yes! Work fine!
Thank you very much for helping.
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<label for="formControlRange">Example Range input</label>
<input type="range" min="1" max="100" value="20" class="form-control-range" id="IW_formControlRange" name="IW_formControlRange"  >
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procedure TIWForm2.IWAppFormCreate(Sender: TObject);
begin
  HiddenFields.AddPair('IW_formControlRange','');
end;
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procedure TIWForm2.IWBS4Button1AsyncClick(Sender: TObject;
  EventParams: TStringList);
var
  S: String;
  oApp: TIWApplication;
begin
  oApp:=WebApplication;
  oApp.ShowMessage(oApp.Request.Params.Text);

  S:=HiddenFields.Values['IW_formControlRange'];
  if not S.IsEmpty  then 
    oApp.ShowNotification(S)
  else 
    oApp.ShowMessage('No Values');
end;