It looks to me like you will need to write some Javascript for this. The only options for button actions are Save, Save and Submit, Cancel, and Javascript. Maybe you could create 2 buttons. One to save the content, and the other with custom Javascript to open the new form.

How about the below method.

Having two lists 'List A' and 'List B'. In my 'List A' form having 'JavaScript' button called 'New Item in List B'.

On click of this button i will open 'List B' new item form and save it.

In 'List A' form on button click call this function

function fnCreateinItemListB()
{
var parentId = NWF$('#'+currentId).val();

//You can get current item id from ListA and store it in new item in List B(for 1 to Many mapping purpose)

var options = {
title: "My Dialog Title",
url: 'http://sites/Lists/LisB/NewForm.aspx?testId='+parentId }; //Pass Id value in url
SP.UI.ModalDialog.showModalDialog(options);
}

In List B get the id value and store it in some field.

NWF$(document).ready(function()
{
var thisId = GetUrlKeyValue('testId');
NWF$('#'+tempId).val(thisId);
});

In this way you can create multiple items in List B from Item in List A.

Thank you for this detailed answer

I´ll build this case based on your example.

Kai

Hi Lakshmi C

This thread is a bit old but it covers my exact question.  I am trying to add a button on a form (Requests) called "Add Employees" which will open up a new record on another list (RequestEmployees) and link it to the ID of the Request item.  I'd like the new item form to remain open.   I copied the java code you provided in a button, but when I click the button, the current (Request) form reopens (no errors) but the new item window does not open and does not appear to have created an item.  I cannot figure out what I am doing wrong.  I have changed all references of "List A" to "Requests" and all references of "List B" to "RequestEmployees".  The url works fine as I am able to copy and paste it into another browser and a new Item opens.  Can you help determine what is wrong.  Below is the code in "Client click" of the button on the Request Form.

function fnCreateinItemRequestEmployees()

{

var parentId = NWF$('#'+currentId).val();
//You can get current item id from Requests and store it in new item in RequestEmployees(for 1 to Many mapping purpose)

var options = {

title: "My Dialog Title",

url: 'https://spteams/sites/SD/SI/ImpRequests/Lists/RequestEmployees/NewForm.aspx?testId='+parentId }; //Pass Id value in url

SP.UI.ModalDialog.showModalDialog(options);

}
In RequestEmployees get the id value and store it in some field.
NWF$(document).ready(function()

{

var thisId = GetUrlKeyValue('testId');

NWF$('#'+tempId).val(thisId);

});