【说明】
单击窗体上的“测试”(cmdTest)按钮，出现一个输入框，要求输入一串字符，将该字符串中的非字母字符删除后，显示在窗体中的一个文本框(txtShow)中。
【程序代码】
Private Sub cmdTest_Click( )
Dim strT1 ,strT2 As String
Dim strCh As (1)
Dim intL As Integer
Dim intl As Integer
strT1 = (2) ("请输入一串字符"，"字符串输入")
intL = (3)
strT2 = " "
For intl = I To intL
strCh = Mid ( strT1, intl, 1 )
If(strCh＞"A"And (4) ) Or (strCh ＞"a" And suCh ＜"z" )Then
strT2 = strT2 + strCh
End If
Next intl
txtShow. Text= (5)
End sub
