.net下拉列表式友情链接

1，前台页面代码：

<asp:DropDownList ID="ddlink" runat="server" AutoPostBack="True" onselectedindexchanged="ddlink_SelectedIndexChanged">
</asp:DropDownList>



2，后台页面代码：

protected void ddlink_SelectedIndexChanged(object sender, EventArgs e)
{
string url = this.ddlink.SelectedValue;
if (url == "" || url.Equals(null))
{
return;
}
else
{
Page.ClientScript.RegisterStartupScript(GetType(), "", "<script>window.open('" + url + "');</script>");
}

｝