简化的VB词频统计程序。程序功能为：在文本框Text1中输入一篇英文文章，在文本框Text2中输入一个英文单词，单机“统计”按钮Command1后，在文本框Text3中显示这个英文单词出现的次数。程序运行界面如图所示。
查找的英文单词由连续的ASCII英文字符（a～z或A～Z）组成。组合词程序会进行分解，如river-small可拆分为2个单词river和small，查找的英文单词不区分大小写。程序代码如下，但加框处代码有错，请改正：
Private Sub Command1_Click()
Dim article As String,f As String,count As Integer
Dim i As Intege，,begin As Integer,s As String
article=Text1.Text : f=Text2.Text : count=0
begin = 1
For i=1 To Len(article)
t = Mid(article,i,1)
If Not(t>="A"And t<="Z" Or t>="a" And t<="z") Then
If i > begin Then
s = 
'①
If LowerCase(f)=LowerCase(s) Then
count = count+1
End If
End If
begin = i + 1
End If
Next i
Text3.Text=Str(count)
End Sub
Function LowerCase(word As String) As String '单词转化为全小写的形式
Dim i As Integer,c As String
For i=1 To Len(word)
c = Mid(word,i,1)
'小写英文字母的ASCII码值比大写字母的值大32
If c>="A" And c<="Z" Then c = 
'②
LowerCase = LowerCase + c
Next i
End Function
以上程序段运行时，为了实现上述功能，加框处代码应改正为：
①{#blank#}1{#/blank#}；②{#blank#}2{#/blank#}。
