*Supportedin part by the Korea ResearchF oundationG;
rant(KRF-99-015-DI0014). Both authorsw ish to thank the refereesf or their valuablec ommentse;
s peciallyp;
ointingo ut no assurancteh at the iteratives equence{ x;
~}r emainsin C in Huang'sp aper [1a] nd suggestinag more generali teratives cheme of (2) which leadst o the currentf ormulationo f our theorem;