powercli script to create datastore alarms

I have a lot of individual datastores that are not all the same size within a cluster. So using the default alarm is not an option. Looking for a script to create an alarm based on utilization and then have it email a notification as it changes status. I found a few scripts online but nothing that i could really get working. Below is what I have pieced together. This script could be way off base...i really don't know.

$storeName = Read-host "Enter Datastore name"

$alarmMgr = Get-View AlarmManager

$entity = Get-Datastore $storeName | Get-View

# AlarmSpec

$alarm = New-Object VMware.Vim.AlarmSpec

$alarm.Name = "Datastore-$storename"

$alarm.Description = "$storename disk utilization"

$alarm.Enabled = $TRUE

#Actions of what i want I want to be notified on

# A trigger for Green->Yellow

Get-AlarmDefinition $alarm.Name | Get-AlarmAction | New-AlarmActionTrigger -StartStatus "Green" -EndStatus "Yellow"

# A trigger for Green->Red

Get-AlarmDefinition $alarm.Name | Get-AlarmAction | New-AlarmActionTrigger -StartStatus "Green" -EndStatus "Red"

# A trigger for Yellow->Green

Get-AlarmDefinition $alarm.Name | Get-AlarmAction | New-AlarmActionTrigger -StartStatus "Yellow" -EndStatus "Green"

# A trigger for Yellow->Red

Get-AlarmDefinition $alarm.Name | Get-AlarmAction | New-AlarmActionTrigger -StartStatus "Yellow" -EndStatus "Red"

# A trigger for Red->Green

Get-AlarmDefinition $alarm.Name | Get-AlarmAction | New-AlarmActionTrigger -StartStatus "Red" -EndStatus "Green"

# A trigger for Red->Yellow

Get-AlarmDefinition $alarm.Name | Get-AlarmAction | New-AlarmActionTrigger -StartStatus "Red" -EndStatus "Yellow"

# Transaction

$trans = New-Object VMware.Vim.AlarmTriggeringActionTransitionSpec

$trans.startstate = "yellow"

$trans.finalstate = "red"

$trans.repeats = $false

$trigger.transitionspecs += $trans

$alarm.action.action += $trigger

# Expression

$expression = New-Object VMware.Vim.MetricAlarmExpression

$expression.Operator = "isAbove"

$expression.red = 9500

$expression.RedInterval = 300

$expression.type = "Datastore"

$expression.yellow = 9000

$expression.yellowinterval = 300

$expression.metric = New-Object VMware.Vim.PerfMetricId

$expression.metric.counterid = 240

$expression.metric.instance = ""

$alarm.expression = New-Object VMware.Vim.OrAlarmExpression

$alarm.expression.expression += $expression

$alarm.setting = New-Object VMware.Vim.AlarmSetting

$alarm.setting.reportingFrequency = 0

$alarm.setting.toleranceRange = 0

# Create alarm.

$alarmMgr.CreateAlarm($entity.MoRef, $alarm)