How to Lock custom setting in salesforce?

Hi Saurabh,

If you look at the documentation on the Lead object, there is no CampaignId field (nor any reference to Campaign. However, if you wanted to loop through the Campaigns a Lead is joined to, there is a CampaignMembers related list (see also the documentation for the CampaignMember object). You could, for example, do:

<apex:page standardController="Lead">
<apex:relatedList list="CampaignMembers" />
</apex:page>
Or if you wanted more granular control over which fields to display:

<apex:page standardController="Lead">
<apex:pageBlock>
<apex:pageBlockTable value="{!Lead.CampaignMembers}" var="member">
<apex:column value="{!member.Campaign.Name}" />
<!-- other columns -->
</apex:pageBlockTable>
</apex:pageBlock>
</apex:page>

Thanks