<form id="form1" name="form1" method="post" runat ="server">

   <input name="funItem" value="1" checked="checked" type="checkbox" />c#
   <input name="funItem" value="2" type="checkbox" />html
   <input name="funItem" value="3" type="checkbox" />javascript
    
    <asp:Button ID="Button1" runat="server" Text="Button" OnClick="Button1_Click1" />

    protected void Button1_Click1(object sender, EventArgs e)
    {
        string argValue = Request.Form["funitem"];
        Response.Write("<script>alert(\"原因：" + argValue + "\");</script>");



    }