Buying a student return ticket online

[Padna]

Student return tickets bought from vending machines (and presumably from booking offices as well) are valid for the return leg on any train within one month, giving great flexibility. I was looking to buy a student return ticket online but have to select a specific train for the return journey. Would such an online ticket only be valid for use on the return train specified at time of booking, or would it actually be valid on any train within a month?

Route is Dublin - Dundalk. The online fare is not discounted.

[Jamie2k9]

Online is still service specific even if no discount, have saw IE saying this before.

[Padna]

Thanks for that. Better to buy from the booking office or TVM rather than online in cases like this so.