Programmatically adding a custom validator?

How do I programmatically add a custom validator? I thought something like this would do:

            Dim validationControl As CustomValidator
            validationControl = New CustomValidator()
            validationControl.ID = "valAllDOBValidator"
            validationControl.ControlToValidate = "dropDOBDD"
            validationControl.Text = "Error Message"
            validationControl.CssClass = "highlight"
            validationControl.Display = ValidatorDisplay.Dynamic
            validationControl.EnableClientScript = "False"
            validationControl.ServerValidate = New ServerValidateEventHandler(AddressOf ALLDOBSValidator_ServerValidate)
            plhOtherInsured.Controls.Add(validationControl)

However I'm getting the following error:

Error      29      'Public Event ServerValidate(source As Object, args As System.Web.UI.WebControls.ServerValidateEventArgs)' is an event, and cannot be called directly. Use a 'RaiseEvent' statement to raise an event.