Validation for 2 or More Texboxes

hi to All
I have 3 texboxes and 3 are numeric valid Data. so for this I have done the code with CompareValidate as follows

Code:

---

<asp:CompareValidator id="StartVal" runat="server" ErrorMessage="?" ControlToValidate="TextBox1"  Type="Integer" Operator="DataTypeCheck"></asp:CompareValidator>

<asp:CompareValidator id="StartVal" runat="server" ErrorMessage="?" ControlToValidate="TextBox2"  Type="Integer" Operator="DataTypeCheck"></asp:CompareValidator>

<asp:CompareValidator id="StartVal" runat="server" ErrorMessage="?" ControlToValidate="TextBox3"  Type="Integer" Operator="DataTypeCheck"></asp:CompareValidator>

---

Is it possible to Write One CompareValidatation for 3 Texboxes Integer Validaion..?

Seems Likes
<asp:CompareValidator id="StartVal" runat="server" ErrorMessage="?" ControlToValidate=" TextBox1,Textbox3,Textbox3 " Type="Integer" Operator="DataTypeCheck"></asp:CompareValidator>