Invoice Email According Payment Method

Hello, thank you in advance for the help you can give me. We have 3 payment methods available, and we want each invoice email display the information of payment method according to which the customer has to default, I tried with this:

{if $ invoice_payment_method eq "Bank Transfer"}
Information for this payment method
{if $ invoice_payment_method eq "Mail In Payment"}
Information for this payment method
{if $ invoice_payment_method eq "2checkout"}
Information for this payment method
{/ if}
{/ if}
{/ if}

But it does not work, is clearly not correct, anyone could help? Ideas? Thank you again!