Add-Type -AssemblyName Microsoft.VisualBasic

# Make buttons\icons variables for easier reading.
$okButton = [System.Windows.Forms.MessageBoxButtons]::OK
$errorIcon = [System.Windows.Forms.MessageBoxIcon]::Error
$infoIcon = [System.Windows.Forms.MessageBoxIcon]::Information

# Ask for a user name
$username = [Microsoft.VisualBasic.Interaction]::InputBox("Enter a username", "Username")

# I like to use the PDC for this stuff, plus it always helps to make sure you're talking to the same
# dc through each command against AD.
try {
    $pdc = Get-ADDomainController -Discover -Service PrimaryDC -ErroAction STOP | Select-Object -ExpandProperty hostname
    Write-Verbose -Message ('Using PDC: {0}' -f $pdc)
}
catch {
    $errorMessage = 'Unable to find PDC: {0}' -f $_.exception.message
    [System.Windows.Forms.MessageBox]::Show($errorMessage,"$username Unlock Error",$okButton,$errorIcon)
}

# word dictionary (ideally you might store this in a file somewhere instead of hard coding)
$words = @('cat','dog','fish','flower','rabbit','horse')

# pick a random word
$word = $words | Get-Random

# Get a random number with 4 digits
$number = '{0:D4}' -f (Get-Random -Maximum 9999)

# Build your password string
$password = "$word$number"
Write-Verbose -Message ('Picked password: {0}' -f $password)

# Create a basic splat to pass in some standard parameters...again easier reading
$cmdSplat = @{
    Identity        = $username
    Server          = $pdc
    ErrorAction     = 'STOP'
}

# Try to unlock the account, and then set the password and for to change at next logon.  If the all of the AD cmdlets work
# then return the confirmation success, otherwise fail.  With the try-catch...it will only move on to the next command if
# the preceding one was a success.  If one fails then it immediately goes to the catch block.
try {
    Unlock-ADAccount @cmdSplat
    Set-ADAccountPassword @cmdSplat -NewPassword (ConvertTo-SecureString -AsPlainText "$password" -Force)
    Set-ADUser @cmdSplat -ChangePasswordAtLogon $true -PasswordNeverExpires $false
    $confirmation = "User account $username has been unlocked, and password has been set to $password"
    [System.Windows.Forms.MessageBox]::Show($confirmation,"$username Unlock Success",$okButton,$infoIcon)
}
catch {
    $errorMessage = 'Failed to set password for {0} on {1}: {2}' -f $username,$dc,$_.exception.message
    [System.Windows.Forms.MessageBox]::Show($errorMessage,"$username Unlock Error",$okButton,$errorIcon)
}