Disable user script check

Created a script that can be used to quickly disable a user. But can someone check the script and give me advice on how to improve the script? There's always room for improvement :-)

functionDisable-User{
    [CmdletBinding(DefaultParameterSetName="Default")]Param(
        [Parameter(Mandatory=$True,Position=0,HelpMessage="Enter the username.")]
        [String]$User,
        [Parameter(Mandatory=$False,Position=1,ParameterSetName="MailboxAccess",HelpMessage="Enter the username requiring access to the user's mailbox.")]
        [Object[]]$GrantMailboxAccessTo
           )# Force en-US settings, IMPORTANT when using different regional settings[Threading.Thread]::CurrentThread.CurrentCulture='en-US'#Enter in administrator credentials$cred=Get-Credential-Credential$runuser#Load ActiveDirectory ModuleIf (!(Get-moduleActiveDirectory )) 
{write-host"Loading Active Directory modules"-foregroundcolor"green"Import-ModuleActiveDirectory
}#Variables Exchange Server$ExchangeServer="http://ExchangeServer/PowerShell/"#Load assembly to show message box    [System.Reflection.Assembly]::LoadWithPartialName("System.Windows.Forms") |out-null#Prompt for confirmation of user account removalif([System.Windows.Forms.MessageBox]::Show("Disable account "+$user+" and remove from all groups?","Question",[System.Windows.Forms.MessageBoxButtons]::YesNo) -eq"Yes")
    {cls"**************************************""*           Select the OU            *""*            1) 30 days OU           *""*            2) 60 days OU           *""*            3) 90 days OU           *""*            4) Do not delete OU     *""**************************************"$a=read-hostIF ($a-eq'1') {write-host"Moved $user to the Delete 30 days OU"-ForegroundColorGreenget-aduser$user|move-adobject-targetpath"OU=Delete 30 Days,OU=Disabled Users,DC=Domain,DC=com"$ou="30 days OU"
 }ElseIf ($a-eq'2') {write-host"Moved $user to the Delete 60 days OU"-ForegroundColorGreenget-aduser$user|move-adobject-targetpath"OU=Delete 60 Days,OU=Disabled Users,DC=Domain,DC=com"$ou="60 days OU"
}ElseIf ($a-eq'3') {write-host"Moving $user to the Delete 90 days OU"-ForegroundColorGreenget-aduser$user|move-adobject-targetpath"OU=Delete 90 Days,OU=Disabled Users,DC=Domain,DC=com"$ou="90 days OU"
}ElseIf ($a-eq'4') {write-host"Moving $user to the Do not delete"-ForegroundColorGreenget-aduser$user|move-adobject-targetpath"OU=Do not delete,OU=Disabled Users,DC=Domain,DC=com"$ou="Do not delete OU"
}#Disable user$Disabled=Get-Aduser$userIf ($Disabled.enabled-eq$true)
        {Disable-ADAccount-Identity$userwrite-host"$user account has been disabled"-foregroundcolorGreen
        }#Change Description"$DisabledBy=$env:username$Date=get-date-uformat"%d-%m-%Y"$UserDescription="Disabled-"+"$Date"+"-"+"$DisabledBy"set-ADUser$user-Description"$UserDescription"write-host"$user description set to $UserDescription"-foregroundcolorgreen#Removes group membership from disabled userswrite-host"Removing group memberships."-ForegroundColorGreen$groups=Get-ADuser$User-Propertiesmemberof|select-ExpandPropertymemberof$groups|Remove-ADGroupMember-members$User-ErrorActionSilentlyContinue-confirm:$False#Start implicit remoting session Exchange serverWrite-host"Starting remote session with $ExchangeServer."-ForegroundColorGreen$s=New-PSSession-ConfigurationNameMicrosoft.Exchange-ConnectionUri$ExchangeServer-AuthenticationKerberos-Credential$credImport-PSSession$s-AllowClobber-DisableNameChecking#Hide user from GALwrite-host"Hiding $user from Global Address List"-ForegroundColorGreenSet-Mailbox-Identity$user-HiddenFromAddressListsEnabled$true#Removing forwardswrite-host"Removing forwarders to external addresses"-ForegroundColorGreenGet-InboxRule-mailbox$user-ErrorAction:SilentlyContinue|Where-Object {$_.ForwardTo-ne$null-and$_.ForwardTo-Notlike"*EmailDomain*"} |remove-inboxrule-confirm:$False
#Remove redirects to external email addresseswrite-host"Deleting redirects to external email adresses"Get-InboxRule-Mailbox$user-ErrorAction:SilentlyContinue|Where-Object {$_.RedirectTo-ne$null-and$_.RedirectTo-Notlike"*EX:/o=EmailDomain*"} |remove-inboxrule-confirm:$False#Remove Activesync AccessIF (Get-CASMailbox$user|where-object {$_.ActiveSyncEnabled-eq$true}) 
      {Set-CASMailbox-Identity$user-ActiveSyncEnabled$falsewrite-host"Disabled Activesync"-foregroundcolorgreen
      }else
        {write-host"Activesync already disabled for $user"-foregroundcolorgreen
        }#Set mailbox accessIf($PSCmdlet.ParameterSetName-eq"MailboxAccess"){$user1=get-aduser$user-Properties*If($GrantMailboxAccessTo-ne$null){Foreach ($GrantMailboxAccessin$GrantMailboxAccessTo){$GrantMailboxAccess1=get-aduser$GrantMailboxAccess-Properties*Add-ADPermission-Identity$user1.DistinguishedName-User$GrantMailboxAccess1.SamAccountName-ExtendedRights'Send-as'-ErrorActionStopWrite-host"$($GrantMailboxAccess1.name) has been granted Send-As access to $($User1.name)'s mailbox."Add-MailboxPermission-Identity$User1.DistinguishedName-User$GrantMailboxAccess1.SamAccountName-AccessRights'FullAccess'Write-host"$($GrantMailboxAccess1.name) has been granted Full Access access to $($User1.name)'s mailbox."
                    }
}
}#Closing current pssessionswrite-host"Closing remote pssession"-ForegroundColorGreenget-pssession|Remove-PSSession#Create new object for logging$date=get-date$obj=New-ObjectPSObject$obj|Add-Member-MemberTypeNoteProperty-Name"Name"-Value$User$obj|Add-Member-MemberTypeNoteProperty-Name"Status"-Value'Disabled'$obj|Add-Member-MemberTypeNoteProperty-Name"Date"-Value"$date"$obj|Add-Member-MemberTypeNoteProperty-Name"OU"-Value"$ou"$obj|Add-Member-MemberTypeNoteProperty-Name"Disabled by"-Value"$DisabledBy"#Adds object to the log array$LogArray+=$obj#Exports log array to CSV file in the temp directory with a date and time stamp in the file name.write-host"exporting CSV file"$logArray|Export-Csv"\\FileShare\Disabled_Users.csv"-NoTypeInformation-Append
}#Exit scriptelse
    {write-warning"No Changes Made"
    }
}