<apex:page standardController="Apttus__APTS_Agreement__c" 
           extensions="APTS_Agreement.AgreementMakePrimaryController" >
    
    <apex:form >
    
        <!--  required fields -->
        <apex:outputText value="{!Apttus__APTS_Agreement__c.Name}" rendered="false"/>
        <apex:outputText value="{!Apttus__APTS_Agreement__c.APTS_Primary__c}" rendered="false"/>
        
        <!--  hidden action buttons -->
        <apex:commandButton id="btnOnLoad" action="{!onLoad}" value="On Load" style="display: none" />
        
        <script>
            var btnOnLoad = document.getElementById("{!$Component.btnOnLoad}");
        </script>
        
        <apex:pageBlock mode="edit" rendered="{!hasErrors}" >
            <apex:pageMessages />
            <apex:pageBlockButtons location="bottom" >
                <apex:commandButton action="{!doCancel}" value="{!$Label.aApttus__APTS_Agreement__cancel}" immediate="true"/>
            </apex:pageBlockButtons>
        </apex:pageBlock>
    </apex:form>
    
    <script>
        // register to invoke the function after the page load
        var hasErrors = "{!hasErrors}";
        if (hasErrors.toLowerCase() == 'false') {
            window.onload = function() { 
                // on load
                btnOnLoad.click();
            };
        }
    </script>
    
</apex:page>