Invitations - dilema - Urgent - please help

[lovenut]

I'm printing invitations but I'm not sure which is the correct wording! I think it should be -

"You are cordingly invited....." Although my sister is convienced it "You are cordially invited...." but that doesn't sound right!

Are either of those right?

Please help this will be the third time the invites have been changed and its driving me mad!