Hi Anh Viet Hai, Co' mo^.t tay computer scientist dda~ no'i: U+o+'c gi` ti`nh ye^u hay mo.i su+. tre^n ddo+`i dde^`u co' the^? reboot ddu+o+.c. To^i chi? muo^'n cung hie^'n mo^.t escape character hoa(.c reboot mode ma` tho^i.( Tru+o+'c khi run a program, dde^` pho`ng bi. treo ma'y). Cheers Aiviet