Format Currency in JavaScript

function formatNumToCurrency(val) {

            var minus = '';

            if (val.toString().indexOf('-') > -1) {

                val = val.toString().replace('-', '');

                minus = '-';

            }

            val = val.toString().replace(/\$|\,/g, '');

            val = val.split(".");

            val[0] = val[0].split("").reverse().join("");

            val[0] = val[0].replace(/(\d{3})/g, "$1,");

            val[0] = val[0].split("").reverse().join("");

            val[0] = val[0].indexOf(",") == 0 ? val[0].substring(1) : val[0];

            val[0] = minus + val[0];

            return val.join(".");

        }

        function formatCurrencyToNum(val) {

            return val.replace(/,/g, "");

        }

 Example

function SetTotalAmount(TotalAmount, Amount, opertaor)

        {

            if (opertaor == "ADD") {

              

                var Tamount1 = formatCurrencyToNum(TotalAmount);

                var Tamount2 = formatCurrencyToNum(Amount);

                TotalAmount = parseFloat(Tamount1) + parseFloat(Tamount2);

             

            } else if (opertaor == "SUB") {

               

            }

          

            return formatNumToCurrency(parseFloat(TotalAmount));

        }