using System; using System.Data; using System.Configuration; using System.Web; using System.Web.Security; using System.Web.UI; using System.Web.UI.WebControls; using System.Web.UI.WebControls.WebParts; using System.Web.UI.HtmlControls; publicpartialclass _Default : System.Web.UI.Page { protectedvoid Page_Load(object sender, EventArgs e) { } protectedvoid DropDownList3_SelectedIndexChanged(object sender, EventArgs e) { if (DropDownList3.SelectedItem.Text =="") { Label1.Text ="你还没有选择!"; } else { Label1.Text="你的籍贯是"+DropDownList1.SelectedItem.Text+DropDownList2.SelectedItem.Text+DropDownList3.SelectedItem.Text; } } }