Sharepoint ClientPeoplePicker Validation

In user control page
<SharePoint:ClientPeoplePicker
            id="ppApprover"
            runat="server" Rows="1" AllowMultipleEntities="false" CssClass="ms-long"/>
                 <asp:CustomValidator ID="cstmVald2" runat="server" ControlToValidate="ppApprover" Display="Dynamic" ValidationGroup="vgCreateSE"
              ValidateEmptyText="true" SetFocusOnError="true" ErrorMessage="Please enter SDU Head(GM & above)" CssClass="ms-error" ClientValidationFunction="peoplvalidator"></asp:CustomValidator>


function peoplvalidator(sender, args) {
          args.IsValid = false;
          var user = $("span.ms-entity-resolved").attr("title");//Returns the Login Name
        
          if (user != undefined) {
              args.IsValid = true;
          }
       
      }