I have both validators on the controls and some custom validators all on the same page. Like this:
<asp:DropDownList ID="ddlStatus" Width="250px" TabIndex="25" runat="server"></asp:DropDownList>
<asp:RequiredFieldValidator ID="rfvStatus" runat="server" ControlToValidate="ddlStatus"
ErrorMessage="Please enter a valid value in the Status field." Display="None">*</asp:RequiredFieldValidator>
Then at the bottom of the page i have these:
<div style="margin-left: 5px; margin-right: 5px">
<asp:CustomValidator ID="cvItemNameExists" runat="server" Display="None" EnableClientScript="false"
ErrorMessage="A System with the same name has already been entered into the system. Please correct yo ...
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