Sharepoint 10 - Restore job-immediate-alerts Job Definition in farm for a site

stsadm -o setproperty -propertyname "job-immediate-alerts" -url "http://sharepoint" -propertyvalue "every 1 minutes between 0 and 59"

Some times we need to get the property value:

stsadm -o getproperty -pn alerts-enabled -url http://sharepoint