Campaigns Module and lead module

I want to match Campaign in campaigns module and a record from lead module automaticly,

I have web form and it gives me the Id of campaign which is in Campaign module so how can match with campaign id which is write on "Campaign_ID" field in Lead record and Id of campaign which is in Campaign module.

lead = zoho.crm.getRecordById("Leads",leadId);

campaign =zoho.crm.getRelatedRecords("Campaigns","Leads",leadId);
info campaign;
campaignId = campaign.getJson("id");
info campaign;
mp =map();
mp.put("Campaign_ID",campaignId);
info zoho.crm.updateRelatedRecord("Campaigns",campaignId.toLong(),"Leads",leadId,mp);