[otrs] SLA tied to Priority

Hi, I am currently looking for a way to automatically tie Priority to SLA. If I update the priority of a ticket then I want to SLA to also be changed. Is this possible? I have seen people mention that it can be done via genericagent.pm does anyone have an example of how to do it this way? What I am trying to achieve is the following: Services: Standard, Premium and Premium Plus. SLA: 1 hour update, 2 hour update, 4 hour update, 24 hour update. So if I have a ticket that is created by a customer with Service = Standard and the Ticket Priority = P5 then the SLA =24 hour update, If I increase the priority to P1 then SLA should automatically =1 hour update. Thanks in advance for your help. Derek Kiely