I am trying to create two buttons that inserts Up and Down on a record by clicking a command button. Here is my code so far:
VF Page:
 

<apex:form id="votingSection">
                       <apex:pageBlock mode="edit">
     <apex:pageBlockButtons location="bottom">
                       <apex:commandButton styleclass="btn-lg btn-data" value="Vote Up"  action="{!voteUp}" reRender="votingSection"/>
                       <apex:commandButton styleclass="btn-lg btn-data" value="Vote Down"  action="{!voteDown}" reRender="votingSection"/>
                        </apex:pageBlockButtons>
                       </apex:pageBlock>
                       </apex:form>

Extension:

  

public class detExt2 {
     
     private final my_object__c myObject;
    
    
            public detExt2() {
                myIdea = [SELECT Id, Vote_Button__c, Name FROM my_object__c
                           WHERE Id = :ApexPages.currentPage().getParameters().get('id')];
            }
         
            public my_object__c getObject() {
                return myObject;
            }
        
            public PageReference voteUp() {
                
                myIdea.Vote_Button__c = 'Up';
                update myObject;
                return null;
            }
              public PageReference voteDown() {
                
                myIdea.my_object__c = 'Down';
                update myObject;
                return null;
            }
        }

Any ideas on how to make this work? Also, I'm trying to figure out how to implement unique votes by user. 

Thanks!