为什么要二次单击后才有效以下我学习教程的得到的代码，本身应是单击查看留言后就能展开留言，单击返回后能自动折叠，可是实际运行后，每个操作都要连续二次单击才能展开或折叠，请问这是为什么：谢谢啦！！！
<%@import namespace="system.data"%>
<%@import namespace="system.data.oledb"%>
<script language="vb" runat="server">
sub play()
dim con as new oledbconnection("provider=microsoft.jet.oledb.4.0;data source="&server.mappath("data.mdb"))
dim constr as string
dim ada as oledbdataadapter
dim ds as dataset
con.open
dim sql as string
sql="select * from mail"
ada=new oledbdataadapter(sql,con)
ds=new dataset()
ada.fill(ds,"留言")
dst.datasource=ds.tables("留言")
dst.databind()
end sub
sub ic_click(sender as object,e as datalistcommandeventargs)
if e.commandsource.id="b1" then
dst.selectedindex=e.item.itemindex
elseif e.commandsource.id="b2"
dst.selectedindex=-1
end if
end sub
sub page_load(sender as object,e as eventargs)
play()
end sub
</script>
<html>
<form runat="server" ID="Form1">
<asp:datalist id="dst" runat="server" onitemcommand="ic_click">
<headertemplate>
<center>
<b>留言簿</b>
</center>
<hr width="85%">
</headertemplate>
<itemtemplate>
<%#container.dataitem("usere")%>
<%#container.dataitem("title")%>
<asp:linkbutton id="b1" runat="server" text="查看留言" />
</itemtemplate>
<selecteditemtemplate>
<center>
姓名：<%#container.dataitem("usere")%>
<asp:linkbutton id="b2" runat="server" text="返回" /><br>
电子邮件：<%#container.dataitem("email")%><br>
留言标题：<%#container.dataitem("title")%><br>
留言内容:<%#container.dataitem("content")%><br>
<br>
</center>
</selecteditemtemplate>
<footertemplate>
<hr>
</footertemplate>
</asp:datalist>
</form>
</html>
