50分求教vb.net 关于javascript弹出对话框 问题！急～～～～～～～

[雅彦]

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
dim i As Integer
i = Directory.GetFiles("D:\upload_database\", 文件名).Length()

If Not (File1.PostedFile Is Nothing) Then
If i = 0 Then//文件不存在直接上传
Try
File1.PostedFile.SaveAs(sourcedb_name)
RegisterStartupScript("MessageBox", "<script language=Javascript>alert('上传文件成功！');</script>")
Session("upload") = 1
Catch exc As Exception
RegisterStartupScript("MessageBox", "<script language=Javascript>alert('上传文件失败，请与管理员联系！');</script>")
Exit Sub
End Try
Else//存在同名文件，则弹出confirm框询问是否覆盖
postedfile = File1.PostedFile

Dim strScript As String
Dim a As Integer

strScript = "<script language='JavaScript'>"
strScript += "var xxx=confirm('文件已存在，是否替换？ ');"
strScript += "if(xxx==false){a=0;"
strScript += "}"
strScript += "if(xxx==true){a=1;"
strScript += "}"
strScript += "</script>"
Page.RegisterStartupScript("confirmUpdate", strScript)

If (a = 1) Then
Try
postedfile.SaveAs(sourcedb_name)
RegisterStartupScript("MessageBox", "<script language=Javascript>alert('上传文件成功！');</script>")
Session("upload") = 1
Catch exc As Exception
RegisterStartupScript("MessageBox", "<script language=Javascript>alert('上传文件失败，请与管理员联系！');</script>")
End Try
Else
Session("upload") = 1
End If
'ok.Visible = True
'cancel.Visible = True
'Button1.Visible = False
'Button2.Visible = False
'Button4.Visible = False
'Button5.Visible = False
End If
End If
End Sub

我现在发现，原本设想会随javascript里confirm按钮事件影响而改变的a值，根本传递不出来，导致后面的if（a＝1）无法执行，请问高手怎么解决？

[雅彦]

顶

[雅彦]

顶一下

[雅彦]

没有人帮忙吗？

[玄之丞]

JS的值,后台取起来是有点困难.
你可以换一个方法
<script language='JavaScript'>
var xxx=confirm('文件已存在，是否替换？ ');
if(xxx==false) {
window.location="不替换.asp";
}else {
window.location="替换.asp";
}
</script>

[雅彦]

顶啊

[雅彦]

ding