Certificate issue with a webservice

hi...we are trying to do URI customization on F5 firepass 4100.. we are trying to map a single webservice to two different certificates...i.e....we have two addresses for the same ip....one of the page does not a require a cert...as it has one by verisign..but wen we try to add the second cert to the same ip from device management>>config>>n/w config>>web services...we are not able to do so....can u guyz suggest some work around for this....we just want to avoid the cert error on the second page