下面程序是用来打印九九乘法表的，请填空。
Private Sub Form_Click()
Dim flag As Integer,i As Integer,j As Integer,Str1$
Str1＝“”
For i＝1 To 9
【 】
For j＝1 To 9
If【 】 Then
str1=str1+Str$(j)+“*”+Str$(i)+“=”+Str$(Val(i*j))
Else
str1＝str1 & Chf(13)
Exit For
End If
Next j
Next i
Print str1
End Sub