Set directory permissions with powershell

gistfile1.ps1

    #create share and set permissions
    New-Item -ItemType Directory $sharePathname


    $inherit = [system.security.accesscontrol.InheritanceFlags]"ContainerInherit, ObjectInherit"
    $propagation = [system.security.accesscontrol.PropagationFlags]"None"

    $permission = 'IIS_IUSRS',"FullControl", $inherit, $propagation, "Allow"
    $accessRule = New-Object System.Security.AccessControl.FileSystemAccessRule $permission
    $acl.SetAccessRule($accessRule)
    
    $permission = 'NETWORK SERVICE',"FullControl", $inherit, $propagation, "Allow"
    $accessRule = New-Object System.Security.AccessControl.FileSystemAccessRule $permission
    $acl.SetAccessRule($accessRule)
       
    
    $acl | Set-Acl $sharePathname