SELECTION-SCREEN编译失败

Question

下面的ABAP代码块出了什么问题？该程序的编译确实会导致错误，但没有显示任何细节。请建议更改代码，使其工作

REPORT  ZSELECTIONSCREENCOMMENTS.
SELECTION-SCREEN BEGIN OF BLOCK B1 WITH FRAME TITLE TIT1.
SELECTION-SCREEN BEGIN OF LINE.
SELECTION-SCREEN POSITION 20.
PARAMETERS: P_MATNR LIKE MARA-MATNR, P_ERSDA LIKE MARA-ERSDA, P_ERNAM LIKE MARA-ERNAM.
SELECTION-SCREEN COMMENT 1(12) COM1 FOR FIELD P_MATNR.
SELECTION-SCREEN COMMENT 1(12) COM2 FOR FIELD P_ERSDA.
SELECTION-SCREEN COMMENT 1(12) COM3 FOR FIELD P_ERNAM.
SELECTION-SCREEN END OF LINE.
SELECTION-SCREEN END OF BLOCK B1.
LOAD-OF-PROGRAM.
TIT1 = 'Selection-Criteria'.
COM1 = 'Material No'.
COM2 = 'ERSDA'.
COM3 = 'ERNAM'.

Answer 1

您试图在一行（BEGIN OF LINE…END OF LINE块）的同一位置放置多个注释，并且在不指定位置的情况下将多个参数添加到该行。