error code invalid_input_syntax - Mailing list pgsql-sql

I wrote a function which generates SQL statements
for INSERTs and UPDATEs, in which I cast the values
to the correct datatype.

Now I want to catch

ERROR:  invalid input syntax for integer: "i"

but although I tried quite a few I can't find the right
error code for this exception.

Is it possible that this error can not be caught?


Thanks
Leo