Insert data to database with Stored Procedure using Web API and AngularJS in ASP.Net MVC

How to insert data into database using stored procedure and web api in angularjs c# without using entity framework?

SuppliersController.cs :

namespace WebApiDemo.Controllers
{
    public class SuppliersController : ApiController
    {
        [HttpPost]
        [ActionName("AddSuppliers")]
        public string insertSupplier(Supplier supplier)
        {
            SqlConnection myConnection = new SqlConnection();
            myConnection.ConnectionString = ConfigurationManager.ConnectionStrings["ERPConnectionString"].ConnectionString;
            SqlCommand sqlCmd = new SqlCommand();
            sqlCmd.CommandType = CommandType.StoredProcedure;
            sqlCmd.CommandText = "INSERT_PURCHASEINVOICE_OPENING";
            sqlCmd.Connection = myConnection;
            sqlCmd.Parameters.AddWithValue("@SupplierId", supplier.SupplierId);
            sqlCmd.Parameters.AddWithValue("@Amount", supplier.Amount);
            sqlCmd.Parameters.AddWithValue("@AsOn", supplier.AsOn);
            sqlCmd.Parameters.AddWithValue("@CreatedBy", supplier.CreatedBy);
            sqlCmd.Parameters.AddWithValue("@CreatedById", supplier.CreatedById);
            myConnection.Open(); 
            myConnection.Close(); 
        }
    }
}

Supplier.cs :

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;

namespace WebApiDemo.Models
{
    public class Supplier
    {
        public int SupplierId { get; set; }
        public Decimal Amount { get; set; }
        public string AsOn { get; set; }
        public string CreatedBy { get; set; }
        public int CreatedById { get; set; }
    }
}

controller.js :

var app = angular.module('myApp', []);
app.controller('supplierController', ['$scope', '$http', supplierController]);
function supplierController($scope, $http) {
    //$scope.loading = true;   
    $scope.add = function () {       
        debugger;
        //$scope.loading = true;
        $http.post('http://localhost:57888/api/Suppliers/AddSuppliers', this.newsupplier).success(function (data) {
            $scope.suppliers = data;
            $scope.newsupplier = '';
        }).error(function (data) {
            $scope.error = "An error has occured while adding supplier! " + data;
        });
    }
}

Regards,

skp.