get button pressed from a submit

You can use the value tag in HTML to send different values for each SUBMIT button on a Form.
You can read the value of each variable received POST data, the same way you can read edit field values.
Here is an example of a "OnDataReceived" event (modify the QuickStart/BrowserUpload example) ...

with TRtcDataServer(Sender) do
begin
if Request.Method='GET' then
begin
Write('<html><body><form enctype="multipart/form-data" method="post">');
Write('Are you sure?');
Write('<input type="answer" value="Yes">');
Write('<input type="answer" value="No">');
Write('<input type="answer" value="Cancel">');
Write('</form></body></html>');
end
else
begin
Request.Params.AddText(Read);
if Request.Complete then
begin
if Request.Params['answer']='Yes' then
Write('You clicked YES')
else if Request.Params['answer']='No' then
Write('You clicked NO')
else
Write('You clicked Cancel?');
end;
end;
end;

Best Regards,
Danijel Tkalcec