I need to copy the ID of a lookup field (Match_with_IP) in the to the ID of a multi-select lookup field in the contact (Match_with_IP).

I have the following script:

record = zoho.crm.getRecordById("Contacts",ID);
M_record = zoho.crm.searchRecords("Deals","(Matched_with_GC:equals:" + ID + ")");

if(record != null)
{
    mp = Map();
    mp.put("Match_with_IP",ipId)
    update = zoho.crm.updateRecord("Contacts",ID,mp);
}

It doesn't seem to populate the multi-select lookup in the Contacts module. Could anyone help me format this properly?

Thanks!