点击控件把表格输出到EXCEL后，再进行操作都是表格输出到EXCEL，应该怎么解决？

做了一个按钮LbtToExcel，点击后把表格table1的内容输出到excel。代码在下面，功能可以实现的，点击后生成了一个Excel文件。但是后面我在页面上点别的按钮，都变成了生成Excel文件，请问该如何解决？多谢指点。
Protected Sub LbtToExcel_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles LbtToExcel.Click
HttpContext.Current.Response.Clear()
HttpContext.Current.Response.AppendHeader("Content-Disposition", "attachment;filename=Excel.xls")
HttpContext.Current.Response.Charset = "GB2312"
HttpContext.Current.Response.ContentEncoding = System.Text.Encoding.UTF7
HttpContext.Current.Response.ContentType = "applicationms-excel;imageJPEG;textHTML;imageGIF;vnd.ms-excelmsword"
Dim tw As System.IO.StringWriter
tw = New System.IO.StringWriter()
Dim hw As System.Web.UI.HtmlTextWriter
hw = New System.Web.UI.HtmlTextWriter(tw)
table1.RenderControl(hw)
HttpContext.Current.Response.Write(tw.ToString())
HttpContext.Current.Response.End()
end sub

页面上点别的按钮，你是不是错误的关联到此段实现的代码？
所以，查此问题不是要看这段代码，而是其它按键的响应函数是如何设定的。