Attach Event Receiver to SharePoint List using PowerShell Script

[System.Reflection.Assembly]::LoadWithPartialName("Microsoft.SharePoint")
$PSshell = Get-PSSnapin "Microsoft.SharePoint.PowerShell" -ErrorVariable err -ErrorAction SilentlyContinue
if($PSshell -eq $null)
{
    Add-PSSnapin "Microsoft.SharePoint.PowerShell"
}

$webUrl = '<<WebUrl>>'

#get web reference
$spWeb = Get-SPWeb $webUrl

#set event receiver properties
$list = $spWeb.Lists["<<ListName>>"]
$assembly = "<<FullyQualifiedAssemblyName>>" #Example: <<AssemblyName>>, Version=<<AssemblyVersion>>, Culture=neutral, PublicKeyToken=<<PublicKeyToken>>
$class = "<<ReceiverClassNameStartingWithNamespaceName>>" #Example: <<NamespaceName>>.<<ClassName>>
$eventType = "ItemAdded" # event type (ItemAdded / ItemUpdated)

#flag to check if the event receiver is already attached with the specified list
$flag=0

#get count of event receivers attached to specified list for checking if the specified event receiver is already attached with the specified list
$eventsCount = $list.EventReceivers.Count - 1

#if there is any event receiver attached to specified list
if($eventsCount -ge 0)
{
    #iterated through the list of event receivers
    for ($i = 0; $i -le $eventsCount; $i+=1)
    {
        #check if the specified event receiver is already attached with the specified list. If yes, set the flag and exit the loop.
        if ($list.EventReceivers[$i].Assembly -eq $assembly -and
        $list.EventReceivers[$i].Class -eq $class -and
        $list.EventReceivers[$i].Type -eq $eventType)
        {
            Write-Host "Event receiver already attached."
            $flag=1
            break
        }
    }
}

#if specified event receiver is not attached with specified list then attach it
if($flag -eq 0)
{
    Write-Host "Attaching event receiver."
    $spEventReceiver = $list.EventReceivers.Add()
    $spEventReceiver.Assembly = $assembly
    $spEventReceiver.Class = $class
    $spEventReceiver.Name = $eventType
    $spEventReceiver.Type = 10001
    $spEventReceiver.SequenceNumber = 10000
    $spEventReceiver.Update()
    Write-Host "Event receiver attached."
}