Set Value of field to be equal of the sum of two fields

[iqbalzahir]

Try this:

   frappe.ui.form.on("[your-doctype-name]", {
        refresh: function(frm) {
        	// make calculation on the fields
    		var a = frm.doc.board_salaries_and_peripherals + frm.doc.board_cash_and_in_kind_benefits;
    		frm.set_value("boarder_total_paid_amounts", a);
    		frm.refresh_field("boarder_total_paid_amounts");
        }
    });