It is often useful to read input from the user but restrict input to a list of choices that you specify. The following script lets you access PowerShell's prompting functionality in a manner that is friendlier than what PowerShell exposes by default. It returns a number that represents the position of the user's choice from the list of options you provide.

#############################################################################
##
## Read-HostWithPrompt
##
## From Windows PowerShell Cookbook (O'Reilly)
## by Lee Holmes (http://www.leeholmes.com/guide)
##
##############################################################################

<#

.SYNOPSIS

Read user input, with choices restricted to the list of options you
provide.

.EXAMPLE

PS > $caption = "Please specify a task"
PS > $message = "Specify a task to run"
PS > $option = "&Clean Temporary Files","&Defragment Hard Drive"
PS > $helptext = "Clean the temporary files from the computer",
>>              "Run the defragment task"
>>
PS > $default = 1
PS > Read-HostWithPrompt $caption $message $option $helptext $default

Please specify a task
Specify a task to run
[C] Clean Temporary Files  [D] Defragment Hard Drive  [?] Help
(default is "D"):?
C - Clean the temporary files from the computer
D - Run the defragment task
[C] Clean Temporary Files  [D] Defragment Hard Drive  [?] Help
(default is "D"):C
0

#>

param(
    ## The caption for the prompt
    $Caption = $null,

    ## The message to display in the prompt
    $Message = $null,

    ## Options to provide in the prompt
    [Parameter(Mandatory = $true)]
    $Option,

    ## Any help text to provide
    $HelpText = $null,

    ## The default choice
    $Default = 0
)

Set-StrictMode -Version 3

## Create the list of choices
$choices = New-Object Collections.ObjectModel.Collection[Management.Automation.Host.ChoiceDescription]

## Go through each of the options, and add them to the choice collection
for ($counter = 0; $counter -lt $option.Length; $counter++)
{
    $choice = New-Object Management.Automation.Host.ChoiceDescription $option[$counter]

    if ($helpText -and $helpText[$counter])
    {
        $choice.HelpMessage = $helpText[$counter]
    }

    $choices.Add($choice)
}

## Prompt for the choice, returning the item the user selected
$host.UI.PromptForChoice($caption, $message, $choices, $default)