help on update for infomix 4.1

I have a little update that is causing me a headache. Pertinent information : Informix version 4.1 running under AIX. The update I want to perform is to update a column from table x and set it equal to a value when the column from table x matches a column from table y ie. update x from x,y set x.col1 = "n" where x.col2 = y.col2 I know FROM is not supported in the update statement for this release of informix. How do we update based on a join? I have tried a subquery in the where clause but informix then complains because I am not allowed to use the table I am updating in the select subquery of the where clause. I have also tried the subquery in the expression list of the set clause ie. update x set x.col1 = (select "n",col2 from y) where x.col2 = y.col2 This also resulted in several syntax statements. Any ideas or suggestions other than upgrade to a current release would be appreciated. pat