get samaccountname from displayname

I have a list of user names ex. last name, First name. Here is my script

foreach ($user in (Get-Content -Path U:\Morningstar\Morningstar.txt))
{Get-ADUser -filter { DisplayName -like “$user” }} | samaccountname

The problem is the -filter part.

it’s working now:

Here is the script:

foreach ($user in (Get-Content -Path U:\Morningstar\Morningstar.txt))
{Get-ADUser -filter { DisplayName -like $user } | Select SamAccountName }