[Serusers] HELP: lookup("aliases")

Hi, ALL: I have an username '1011' on my subscriber table and I want my 1011 can map to a name 'charles' for alias on my aliases table. all subscribers and aliases are the same domain. But I use lookup("aliases"), and I have a record on aliases table. ------------------------------------------------------------------------------------------------- username domain contact ------------------------------------------------------------------------------------------------- 1011 sip.company.com charles(a)sip.company.com ------------------------------------------------------------------------------------------------- I dial to 1011 from another UAC and register on the same ser sip proxy. It works fine. But I dial to charles. It failed. Does anybody know what it happen and how to solve it? -- Best Regards Charles