光标操作

DATA: w_fname(20) TYPE c,       w_val(10) TYPE c. PARAMETERS: p1(10) TYPE c,             p2(10) TYPE c,             p3(10) TYPE c. AT SELECTION-SCREEN.   CHECK sy-ucomm IS INITIAL.   GET CURSOR FIELD w_fname VALUE w_val.   CHECK w_val IS INITIAL.   "如果没有输入   CLEAR w_fname. AT SELECTION-SCREEN OUTPUT.   CASE w_fname.     WHEN 'P1'.       CLEAR w_fname.       SET CURSOR FIELD 'P2'.     WHEN 'P2'.       CLEAR w_fname.       SET CURSOR FIELD 'P3'.   ENDCASE.       AT SELECTION-SCREEN OUTPUT以外，不好用哈