<td>
    <SharePoint:ClientPeoplePicker VisibleSuggestions="5" Rows="1" ID="ppContractManager"
    Enabled="true"   Required="true" runat="server"
    ValidationEnabled="true" AllowMultipleEntities="true" Width="245px" />

    <asp:RequiredFieldValidator EnableClientScript="true" Display="None"
    ValidationGroup="QC" ID="rfvppContractManager" ControlToValidate="ppContractManager"
    runat="server" ValidateRequestMode="Enabled"   ValidateEmptyText="true"
    ErrorMessage="Enter Contract Manager" />
</td>

<SharePoint:PeopleEditor ID="user" runat="server" SelectionSet="User" AllowEmpty="false" Enabled="false" MultiSelect="false" ValidatorEnabled="false"/>

function plpckProjectSponsorFun() {
    var err = "";
    var pickval = document.getElementById('<%=ppContractManager.ClientID%>' + "_hiddenSpanData").value;
    if (pickval != "" && pickval != "&#160;" && pickval != "&nbsp;" && pickval != " ") {
        var v1 = Page_ClientValidate("QC");
        if (!v1) {
            return false;
        }
    }
}