Caption:='this is first line<br>this is second line';
Caption:='this is first line'#13#10'this is second line';
Both approaches do not work.
Why do you need this?
One possible solution I think:
procedure TMainForm.UniFormReady(Sender: TObject);
begin
with UniPanel1 do
begin
Caption := 'this is first line<br>this is second line';
JSInterface.JSCode('Ext.get('#1'.id+"_td").setHtml("'+ Caption +'");');
end;
end;