编写一个对输入字符进行转换的程序.转换规则为:将大写字母转换成小写,小写转换为大写,空格不转换,其他转换为"*".要求没输入一个字符就进行判断转换.

我自己写了个
commandgroup1的click事件:
n=this.value
do case
case n=1
thisform.timer1.enabled=.t.
thisform.timer2.enabled=.f.
case n=2
thisform.timer1.enabled=.f.
thisform.timer2.enabled=.t.
endcase
timer1的timer事件:
thisform.text1.value=time()
thisform.label1.caption=""
timer2的timer事件:
t=hour(datetime())
if t>=13
thisform.label1.caption="下午"
if t>=22
thisform.text1.value=allt(t-12)+substr(datetime(),11,6)
else
thisform.text1.value=time()
endif
else
thisform.label1.caption="上午"
thisform.text1.value=time()
endif
运行timer2老出错
错哪了?