set password in join domain script

I whant to create a script to when it runs it joins domain automaticaly.

when i do the following $Admin = get-credential domain\user, it popsup with a screen to fill in the password.
is it possible to make the script so that if i run it joins domain auto?

Script so far below

$Admin = get-credential domain\admin [password?]

Add-Computer -DomainName domainname.local -Credential $admin -restart

not tested as i dont have my laptop but this should work / at least hold the credentials

$Username = "Domain\Username"
$Password = ConvertTo-SecureString "Password" -AsPlainText -Force
$Admin = new-object -typename System.Management.Automation.PSCredential -argumentlist $username, $password

Add-Computer -DomainName domainname.local -Credential $admin -restart

Seems Legit, i’m gonna test this and will reply back if it worked.
Thank you so far Mark.

Kind regards, Jeremy

@ Mark Prior.

Is it possible to build in the script that powershell will be elevated to administrator?

quite a few options discussed here that should help

http://stackoverflow.com/questions/7690994/powershell-running-a-command-as-administrator

cheers