Returns the user record number (0-65535) for user name user or -1 if user is not registered on this system.
See also: U_Bdl, U_BdlDay, U_Bul, U_Fdl, U_Ful, U_InConf, U_LDate, U_LDir, U_Lmr, U_Logons, U_LTime, U_MsgRd, U_MsgWr, U_Name, U_PwdHist, U_PwdLc, U_PwdTc, U_Stat, U_TimeOn