Sorry for late response.
One possible solution:
1. UniEdit1...
function keydown(sender, e, eOpts)
{
var customVar = ajaxRequest(sender, 'getCVar', {}, false).responseText;
alert(parseInt(customVar) + 5);
}
2.
procedure TMainForm.UniEdit1AjaxEvent(Sender: TComponent; EventName: string;
Params: TUniStrings);
begin
if EventName = 'getCVar' then
begin
// Instead of 10, "any variable"...
UniSession.SendResponse(10.ToString());
end;
end;