Multiple input with Usernames

Hi everybody,

I tried several things but I already didn´t found a solution for my problem.

I made a script which creates folders, security groups etc.

Now I try to make input where I can write several Username into.

Example:

$elementrw = read-host "please enter the usernames (username1, username2, ...))"

function Get-Something
{
  param
  (
    [Parameter(Mandatory=$true,ValueFromPipeline=$true)]
    [Object[]]
    $InputObject
  )
 
  process
  {
    $InputObject | ForEach-Object {
      $element = $_
      Add-ADGroupMember -Identity $RWGROUP -Members $element
    }
  }
}

if ($elementrw -eq "0")
    {
        Write-Output "no users available"
    }
else
    {
        get-something -InputObject $elementrw
    }

If I do it this way, I get an error message:

Add-ADGroupMember : Unter "DC=domain,DC=corp, kann kein Objekt mit der ID "username1, username2" gefunden werden.
In Zeile:16 Zeichen:7
+       Add-ADGroupMember -Identity $RWGROUP -Members $element
+       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : ObjectNotFound: (username1, username2:ADPrincipal) [Add-ADGroupMember], ADIdentityNotFoundException
    + FullyQualifiedErrorId : SetADGroupMember.ValidateMembersParameter,Microsoft.ActiveDirectory.Management.Commands.AddADGroupMember

But if I enter (for testing) the usernames directly to get-something -InputObject it works ...

Example:

get-something -InputObject username1, username2, username3

so can anybody help me with the probleme?!

Many thanks everybody