关于焦点离开时，customervalidator没被触发的问题？

代码如下：
<asp:TextBox id="userid" runat="server" MaxLength="12" CausesValidation="True"></asp:TextBox>
<asp:CustomValidator ID="CustomValidator1" runat="server" ControlToValidate="userid"
Display="Dynamic" EnableClientScript="true" ErrorMessage="用户已存在" OnServerValidate="CustomValidator1_ServerValidate1"
SetFocusOnError="True"></asp:CustomValidator>

protected void CustomValidator1_ServerValidate1(object source, ServerValidateEventArgs args)
{
string username = userid.Text.ToString();
string str = "select count(*) from blog_user where user_name=" + username;//这里测试过了，没问题

if (odb.sum(str) > 0)
{
args.IsValid =false;
}
else
{
args.IsValid = true;
}
}

现在给我改的不管args.IsValid是true还是false都不会出来错误信息了

[此贴子已经被作者于2007-11-9 10:37:42编辑过]