Plz Help me Oracle stored procedure for doing wildcard search

Hi. I am creating a search page and using a dynamic query. I plan to allow users to perform wildcard search on a bunch of fields. So, if someone enters 123 or 12* or *12 as the Airbill Id, I want my stored procedure to look for the * and do a wild card search, if not, just do an exact match. Please Suggest me!! Thanks in Advanced.