Alerts not working in Interaction Management in HP Service Manager

I added alert def and added to the particular phase in Service Desk Workflow and then created a interaction for test but no alerts are working on interaction, i tried to view alert logs by clicking view alert logs in more option and their are no logs on that interaction...Please help in configuring alerts in Interaction Management in service desk Also need help on Notifications like configuring notifications for service desk module, i want to send notification when their is no work/action on interaction ticket for last 24hrs.