I try to configure nagios in the following way

for every service (for example "mysql seconds behind master") I need to define few levels of escalations, when level is warning I want to send only email and when level is critical I want to send email and sms .

What is the right way to do this?

Do be stick we the levels definition (critical or warning), if there is different way to differentiate email level and sms level of escalation?

Thanks!