#import SQL Server module
Import-Module SQLPS -DisableNameChecking

#replace this with your instance name
$instanceName = "localhost"
$server = New-Object -TypeName Microsoft.SqlServer.Management.Smo.Server -ArgumentList $instanceName

$jobserver = $server.JobServer
#for purposes of our exercise, we will drop this
#alert if it  already exists
$alertname = "Test Alert"
$alert = $jobserver.Alerts[$alertname]

#if our test alert exists, we will drop it first
if($alert)
{
  $alert.Drop()
}

#Alert accepts a JobServer and an alert name
$alert  = New-Object  Microsoft.SqlServer.Management.Smo.Agent.Alert $jobserver, $alertname
$alert.Severity = 10

#Raise Alert when Message contains
$alert.EventDescriptionKeyword...