How can I log the result of a Powershell script?

Hi,

I'm using the script below to change around 1000 MailboxFolderPermissions. I want to know how I can log the results in a txt-file. I tried to add ">D:\log.txt" and on the following row ">>D:\log.txt" but it doesn't log any text in D:\log.txt.

Anyone knows how I can log the results? 

Set-MailboxFolderPermission -Identity <alias1>:\calendar -User default -AccessRights LimitedDetails

Set-MailboxFolderPermission -Identity <alias2>:\calendar -User default -AccessRights LimitedDetails

Kwokwah