problems with hashtable(how to get keys knowing values)

[admin]

Hi,I have a problem and any help would be greatly appreciated!I have hashtable like that:Hashtable category = new Hashtable();category.put("XREF_STATE_CODE", "Global Setup");category.put("XREF_STATE_COUNTRY", "Global Setup");category.put("PROPERTY_CONTACT", "Property Setup");category.put("PROPERTY_DESC", "Property Setup");category.put("RENTABLE_GROUP", "Property Setup");category.put("RENTABLE_DAY", "Property Setup");category.put("HMA_STATEMENT", "Invoicing");category.put("RA_TRANSACTION", "Invoicing");category.put("RA_INVOICE", "Invoicing");category.put("INVOICE_COMMENT", "Invoicing");where key is table_name and value is a category which each table_name relatedto. Knowing table_name I can easily to get value(category). The problem ishow knowing category(value of hashtable) to get table_names (keys) that relatedto this category.Thanks in advance.Tanya.