syntax for CASCADE

Am in the process of converting a schema from Access to Informix S/E and cannot seem to find the syntax for SQL statement to do an "ON UPDATE CASCADE" (there is the equivalent "ON DELETE CASCADE" statement). I have looked through all on-line Informix/SQL documentation without any luck. Any ideas/help? (This does not seem very unreasonable to want to build into the schema after all!) TIA -- Greg Silverman <gms@tc.umn.edu> University of Minnesota Cancer Center