Tip Box in checkout

[Seroxat]

Hi, i'm trying to make an online pizza ordering website and I wanna add a tip box on checkout page with Drop Down menu like 1$ - 2$ it should also be shown in notify e-mails so we can see which order number gave tips. So is there any component or module or plugin for that, how can i do that ? Thanks in advance.

VM: 2.0.24 Joomla: 2.5.14 Stable