报表合并，用append出现下列问题，求大神帮忙！

.   append using "F:\软件学习\计量（袁）\资产负债表\basheet1.dta",force  
(note: variable asset was str17 in the using data, but will be double now)
(note: variable liability was str17 in the using data, but will be double now)
(note: variable quety was str18 in the using data, but will be double now)
(note: variable code was str6, now str12 to accommodate using data's values)
(label id already defined)


请问存在的问题怎么解决？ 我从国泰安下载数据，运行是第2个资产负债表，上面basheet1是第1个资产负债表，2合并1，出现上面的问题