Any idea why the popup is not closing in the below code.  This is code for my Popuup Window from "New Vehicle" related
list of Case.  It opens fine, but I want it to close if I hit the cancel button or Save -- after saving the information.

Serial_Number__c is Required

When I hit "Close"  It says pls fill in the Required Fields.
Also When I hit "Save" it does not close.
Any idea Why ??
 

<apex:page standardController="Case_Vehicle__c" sidebar="false" >

        <script language="JavaScript" type="text/javascript">
        function closeAndRefresh()
        {
            window.close();
            window.opener.location.reload();
        }
        </script>

    <apex:form >
   
        <apex:pageBlock title="Case Vehicle"  mode="edit">
            <apex:pageBlockButtons >
                <apex:commandButton action="{!save}" value="Save" oncomplete="closeAndRefresh()"/>
                <apex:commandButton value="cancel" onclick="closeAndRefresh()" />
              
            </apex:pageBlockButtons>
            <apex:pageBlockSection title="Vehicle Information" columns="2">
                <apex:inputField value="{!Case_Vehicle__c.Serial_Number__c}"/>
                <apex:inputField value="{!Case_Vehicle__c.VIN__c}"/>
                <apex:inputField value="{!Case_Vehicle__c.Case__c}"/>
                <apex:inputField value="{!Case_Vehicle__c.Color__c}"/>
                <apex:inputField value="{!Case_Vehicle__c.Country__c}"/>
                <apex:inputField value="{!Case_Vehicle__c.Driver_Name__c}"/>
                <apex:inputField value="{!Case_Vehicle__c.Engine_Hours__c}"/>
                <apex:inputField value="{!Case_Vehicle__c.Fuel_Type__c}"/>
                <apex:inputField value="{!Case_Vehicle__c.Harness_Type__c}"/>
                <apex:inputField value="{!Case_Vehicle__c.License_State__c}"/>
                <apex:inputField value="{!Case_Vehicle__c.License_Plate__c}"/>
                <apex:inputField value="{!Case_Vehicle__c.YMM__c}"/>
                <apex:inputField value="{!Case_Vehicle__c.Odometer__c}"/>
                <apex:inputField value="{!Case_Vehicle__c.Vehicle_Label__c}"/>
               
            </apex:pageBlockSection>
        </apex:pageBlock>
       
    </apex:form>
</apex:page>