Help with short translation (spanish)

Hi, i dont hold out much hope for this request on the spanish page due to the absence of traffic there so i'm hoping the mods will allow me to post this in after hours since it is a matter of urency for me >_<

going to a gig in barcelona and we were hoping to swap our tickets (seated for standing) with someone outside the venue beforehand.

What i'm looking to do is print out a sign in spanish reading something like:

"Want to swap tickets. Have two seated tickets, would like two standing tickets!"

Obviously it does not have to be this word for word, just something that is snappy, to the point and that a spanish crowd would understand.

Any help would be very much appreciated!