Multiple inputs in PowerShell

I have script where I ask for the user ID and I use $userName in all my commands.

Now I would like to also have the option to enter the PC name and turn back to the user ID, (if the user ID cannot be found it displays a custom error message). The problem is that $userName is unique and should contain the user ID and not the PC name. Side-note: PC names are imported with a CSV file. Also all pc names are starting with BN.

Do {

# Check if a username is entered on the command prompt
Do {
    Write-Host "Enter the user ID: " -ForegroundColor Cyan -NoNewline
    $userName = Read-Host
} Until ($userName)

# Check if the user exists in Active Directory
$user = $(
         try {
                Get-ADUser -Server domainlocal -Filter "samaccountname -eq '$userName'"
         }
         catch {
                $null
         }
   )

# Output the result for the check in Active Directory
If (!$user) {
    Write-host  "The user does not exist, please try again."   -ForegroundColor Red 
} 
Else {
    Write-host "User found in Active Directory, loading options..." -ForegroundColor Yellow -NoNewline
    ''
}} Until ($user)

To get the user ID with the PC name it should be like this:

write-host "enter PC Name" 
$PCnaming = Read-Host

$userName = $Computernames.Where({$_. "PC name" -like $PCnaming })."User ID"

$userName

Solution

You can ask the user to prefix PC names with something that'll allow you to distinguish it from a user ID:

Do {
    Write-Host "Enter the user ID (or enter a computer name prefixed with 'PC:'): " -ForegroundColor Cyan -NoNewline
    $userName = Read-Host
    if($userName -like 'PC:*'){
        $PCnaming = $userName -replace '^PC:'
        $userName = $Computernames.Where({$_. "PC name" -like $PCnaming })."User ID"
    }
} Until ($userName)

If the user enters someusername it'll be stored in $userName, but if the user enter pc:computername, the loop will attempt to extract the user ID associated with computername