Deal Create button on Contact view page assignes the Deal to Account record only

Hi,

I've added a function as button to my CRM which should create a deal record from a contact view page. It roughly works. However the new deal record has Account popullated field but not Contact (it looks like the Contact lookup field in Deal module couldn't be popullated with that code). What is more, the Deal is assigned to Account and I want to assing it to Contact.

Here is the code

contDetails = zoho.crm.getRecordById("Contacts",contId.toLong());

DealMap = Map();

DealMap.put("Deal_Name",ifnull(contDetails.get("First_Name"),""));

DealMap.put("Contact_Name",ifnull(contDetails.get("First_Name" + "Last_Name"),""));

DealMap.put("Account_Name",ifnull(contDetails.get("Account_Name"),""));

DealMap.put("Account_Name",ifnull(contDetails.get("Owner"),""));

DealMap.put("Owner",ifnull(contDetails.get("id"),""));

DealMap.put("Stage","Nowa Szansa");

DealCreate = zoho.crm.createRecord("Deals",DealMap);

info DealCreate;

return "";

Any idea what to change? Suggestions are welcome.