大神指导下哪里错了 运行的视乎显示

n="thisform.text1.value"
if n<0 or n>100
thisform.text2.value="非法数据"
else
do case
case n>=85 and n<=100
thisform.text2.value="优秀"
case n>=60 and n<85
thisform.text2.value="合格"
case n>=0 and n<60
thisform.text2.value="不合格"
endcase
endif

n=thisform.text1.value
if n<0 or n>100
thisform.text2.value="非法数据"
else
do case
case n>=85 and n<=100
thisform.text2.value="优秀"
case n>=60 and n<85
thisform.text2.value="合格"
case n>=0 and n<60
thisform.text2.value="不合格"
endcase
endif

thisform.text1.value=999

共性错误
数据类型问题，没有很好掌握

n=thisform.text1.value
if n<0 or n>100
thisform.text2.value="非法数据"
else
do case
case Between(n,85,100)
thisform.text2.value="优秀"
case Between(n,60,84)
thisform.text2.value="合格"
case Between(n,0,59)
thisform.text2.value="不合格"
endcase
endif