[Database] [Sybase] How to implement trim() in Sybase?

Problem
If I would like to remove unnecessary space from a column value, how to do it in Sybase?

Sybase does not have trim function which provide by Oracle.

Error: Function 'trim' not found. If this is a SQLJ function or SQL function, use sp_help to check whether the object exists (sp_help may produce a large amount of output).

SQLState:  S1000
ErrorCode: 14216

How-To
You can use ltrim and rtrim to fulfill this requirement:

select ltrim(rtrim('   123aa       '))