Two validation messages appear together

I have a textbox in which a user have to enter a date. This text is validated against empty data (RequiredFieldValidator1), valid date dd/MM/yy (CompareValidator1) and not early than submission date (CompareValidator2). Everything works ok, but when I test invalid date, both CompareValidator1 and CompareValidator2 message errors appear. How can I avoid this?

<asp:TextBox ID="txtExpiryDate" runat="server" OnFocus="this.valu ...