At 01:31 PM 31/01/2008, you wrote:

>Dear All,
>
>I need a function to check a string whether it exist
>or not in another string variable. Usualy in another
>programming language this function called AT().

Why not just use the standard SQL predicate CONTAINS [or CONTAINING] ?

> because I need it to validate a routine in insert and update trigger.

if (new.quotation CONTAINS ('SOMETHING UNDESIRABLE')) then
...

>Any comment is greatly appreciated.

The search argument is case-insensitive.

./heLen