Installing a backup/restore for Azure VM

Hi guys,

I am trying to configure a backup/restore for my Azure VM and could not add a new container with Azure Powershell console.

I actually follow the following steps from the link bellow:
http://blogs.technet.com/b/heyscriptingguy/archive/2014/01/24/create-backups-of-virtual-machines-in-windows-azure-by-using-powershell.aspx

I have been receiving the error (screenshot provided as an attachment):
------------------------------------------------------
New-AzureStorageContainer : Can not find your azure storage credential. Please set current storage account using
"Set-AzureSubscription" or set the "AZURE_STORAGE_CONNECTION_STRING" environment variable.
At line:1 char:1
+ New-AzureStorageContainer -Name $backupContainerName -Permission off
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : InvalidArgument: (:) [New-AzureStorageContainer], ArgumentException
    + FullyQualifiedErrorId : ArgumentException,Microsoft.WindowsAzure.Commands.Storage.Blob.Cmdlet.NewAzureStorageCon
   tainerCommand

Could you please help me with that and tell me if there is another way to backup/restore automatically (such as a daily backup).

Thank you in advance.

Regards,

Florian