wpa256 ascii

bought daughter computer for xmas so thought we'd set it up in advance ie connect to internet etc except it won't. selected search for wireless which it did,found ours then clicked on connect but it gets stuck on pending. it is a asus eepc with linux. our wireless is wpa encrypted. the eepc asks us for our passphrase which we type but it comes up with the wpa256 ascii message. so it wont connect. what do we do???