Admin group membership switch powershell script

[CmdletBinding()]
param($user)

# This checks if the shell is an admin shell, otherwise summons the script in an admin shell
If (-NOT ([Security.Principal.WindowsPrincipal][Security.Principal.WindowsIdentity]::GetCurrent()).IsInRole([Security.Principal.WindowsBuiltInRole] "Administrator"))
{
    $arguments = "& '" + $myinvocation.mycommand.definition + "'"
    Start-Process powershell -Verb runAs -ArgumentList ($arguments, [Security.Principal.WindowsIdentity]::GetCurrent().Name)
    Break
}
else
{
    $user = [Security.Principal.WindowsIdentity]::GetCurrent().Name
}

# Running as an admin shell from this point bellow

$group = [ADSI]"WinNT://$($user.Substring(0,$user.IndexOf('\')))/Administrators,group"
$user = $user.Replace("\","/")

# Tries to add the current user to the admin group, if an exception it thrown, it means the user is already admin, so we remove it instead.
try{
    $group.Add("WinNT://$user,user")
    Write-Host "Added $user to administrators group"
}
catch{
    $group.Remove("WinNT://$user,user")
    Write-Host "Removed $user from administrators group"
}
sleep 5