Hi there

Am a newb to Apex/VF.  I'm trying to populate a multi-select picklist "Site Categories", from a custom object - Site_Categories__c.

I want to add this field to the Lead object.

Thanks to some wonderful SF people out there, I've been able to succeed in the first part, however, I'm not sure how to add it to the Lead object, plus be able to edit and save the values chosen to the Lead records.

All help appreciated!  Code below:

Controller

public with sharing class MultiSelectPicklist {

    private final Site_Categories__c scats;

    public MultiSelectPicklist(ApexPages.StandardController controller) {
            
       this.scats= (Site_Categories__c)controller.getSubject();

    }

 
    //public Site_Categories__c scats;
    
    public List<SelectOption> LeftSelectList {get;set;}
    public List<SelectOption> RightSelectList {get;set;}
 
    public List<string> LeftSelectedValues {get;set;}
    public List<string> RightSelectedValues {get;set;}
 
    public MultiSelectPicklist()
    {
        LeftSelectList = new List<SelectOption>();
        RightSelectList = new List<SelectOption>();
        

        for(Site_Categories__c scats : [select id,category__c from site_categories__c order by category__c ASC])
        {
            LeftSelectList.add(new SelectOption(scats.Id, scats.category__c)) ;
        }
        
        RightSelectList.add(new SelectOption('-- None --','-- None --'));
    }
 
    public void MoveRight()
    {
        if (LeftSelectedValues != null && LeftSelectedValues.size() > 0)
        {
            
            //Clear RightSelectedValues
            RightSelectedValues = new List<string>();
            
            //Remove 'None' value from RightSelectList            
            if(RightSelectList != null)
            {
                for(integer i = 0; i < RightSelectList.size(); i++)
                {
                    RightSelectList[i].getValue();
                    RightSelectList.remove(i);
                }
            }
            
            for (integer i =0; i < LeftSelectList.size(); i++)
            {
                for (integer si =0; si < LeftSelectedValues.size(); si++)
                {
                    if (LeftSelectList[i].getValue() == LeftSelectedValues[si])
                    {
                        //Remove the SelectOption from LeftSelectList and add it to RightSelectList

                        RightSelectList.add(LeftSelectList.remove(i));
 
                        //Remove the SelectOption from LeftSelectedValues and add it to RightSelectedValues
                        RightSelectedValues.add(LeftSelectedValues[si]);
 
                    }
                }
 
            }
            //Clear LeftSelectedValues
            LeftSelectedValues = new List<string>();
            LeftSelectList.add(new SelectOption('-- None --','-- None --'));
        }
    }
 
    public void MoveLeft()
    {
        //Remove 'None' value from LeftSelectList
        if(LeftSelectList != null)
            {
                for(integer i = 0; i < LeftSelectList.size(); i++)
                {
                    LeftSelectList[i].getValue();
                    LeftSelectList.remove(i);
                }
            }
            
        if (RightSelectList != null && RightSelectList.size() > 0)
        {
            //Clear LeftSelectedValues
            LeftSelectedValues = new List<string>();

            for (integer i =0; i < RightSelectList.size(); i++)
            {
                for (integer si =0; si < RightSelectedValues.size(); si++)
                {
                    if (RightSelectList[i].getValue() == RightSelectedValues[si])
                    {
                        //Remove the None value from the LeftSelectList
                        //LeftSelectList.remove(i);
                                    
                        //Remove the SelectOption from RightSelectList and add it to LeftSelectList
                        LeftSelectList.add(RightSelectList.remove(i));

 
                        //Remove the SelectOption from RightSelectList and add it to LeftSelectedValues
                        LeftSelectedValues.add(RightSelectedValues[si]);
                    }
                }
 
            }
            //Clear RightSelectedValues
            RightSelectedValues = new List<string>();
            RightSelectList.add(new SelectOption('-- None --','-- None --'));
        }
    }
    

}

Page

<apex:page controller="MultiSelectPicklist" sidebar="false">
<apex:form >
     <apex:pageBlock mode="edit">
 
        <table cellpadding="3">
            <tr>
                <td colspan="2"><apex:outputLabel style="font-weight: bold;">Site Categories</apex:outputLabel></td>
            </tr>
            <tr>
                <td>
                    <apex:selectList size="5" multiselect="true" value="{!LeftSelectedValues}" id="LeftSelectList">
                        <apex:selectOptions value="{!LeftSelectList}"/>
                    </apex:selectList>
                </td>
                <td style="vertical-align:middle;text-align:center;">
                    <apex:commandButton value=">"  action="{!MoveRight}" reRender="LeftSelectList,RightSelectList"/>
                    <br />
                    <apex:commandButton value="<" action="{!MoveLeft}" reRender="LeftSelectList,RightSelectList"/>
                </td>
                <td>
                    <apex:selectList size="5" multiselect="true" value="{!RightSelectedValues}" id="RightSelectList">
                        <apex:selectOptions value="{!RightSelectList}"/>
                    </apex:selectList>
                </td>
 
            </tr>
        </table>
 
    </apex:pageBlock>
</apex:form>
</apex:page>

Please help!

Thank you :)

R