<div class="form-group" >
            <label for="" class="col-sm-2 control-label"><h4><b>Vendor</b></h4> </label>

            <div class="col-sm-3" align="right">
                <select class="form-control" id="vendor" name="vendor" required>
                    <option value="">Please Select Vendor</option>
                </select>

            </div>
        </div>

        <div class="col-sm-3" >
            <div class="form-group">
                <label for="" class="col-sm-2 control-label">Purchase Date</label>

                <input type="date" class="form-control" id="start_date" name="p_date" placeholder="Purchase Date"  required>
            </div>
        </div>
</div>

    <div class="col-sm-4">
        <div class="col s12 m6 offset-m4">
            <div class="form-group" align="left">
                <label class="form-label">Total</label>
                <input type="text" class="form-control" placeholder="Total" id="total" name="total" size="30px" required="">
            </div>

            <div class="form-group" align="left">
                <label class="form-label">Pay</label>
                <input type="text" class="form-control" placeholder="Balance" id="pay" name="pay" size="30px" required="">
            </div>

            <div class="form-group" align="left">
                <label class="form-label">Due</label>
                <input type="text" class="form-control" placeholder="Due" id="due" name="due" size="30px" required="">
            </div>
            <div class="form-group" align="left">
                <label class="col-sm-2 control-label">Status</label>


                <select class="form-control" id="payment" name="payment"
                        placeholder="Project Status" required>
                    <option value="">Please Select</option>
                    <option value="1">Cash</option>

                    <option value="2">Cheque</option>
                </select>
            </div>


            <div class="card" align="right">

                <button type="button" id="save" class="btn btn-info" onclick="addProject()">Add
                </button>
                <button type="button" id="clear" class="btn btn-warning" onclick="reSet()">Reset</button>
            </div>
</form>

        </div>
    </div>

function addProject() {

        if ($("#frmProject").valid())
        {
            var _url = '';
            var _data = '';
            var _method;
            if (isNew == true) {
                _url = 'add_purchase.php';
                _data = $('#frmProject').serialize();
                _method = 'POST';

            }
            else {
                _url = 'update_project.php',
                    _data = $('#frmProject').serialize() + "&project_id=" + project_id;
                _method = 'POST';
            }
            $.ajax({
                type: _method,
                url: _url,
                dataType: 'JSON',
                data: _data,
                beforeSend: function () {

                    $('#save').prop('disabled', true);
                    $('#save').html('');
                    $('#save').append('<i class="fa fa-spinner fa-spin fa-1x fa-fw"></i>Saving</i>');
                },
                success: function (data) {
                    $('#frmProject')[0].reset();
                    $('#save').prop('disabled', false);
                    $('#save').html('');
                    $('#save').append('Add');
                   // get_all();
                    var msg;
                    if (isNew)
                    {
                        msg="Registation Successfully Created";
                    }
                    else{
                        msg="Registation Successfully Updated";

                    }
                    $.alert({
                        title: 'Success!',
                        content: msg,
                        type: 'green',
                        boxWidth: '400px',
                        theme: 'light',
                        useBootstrap: false,
                        autoClose: 'ok|2000'
                    });
                    isNew = true;
                },
                error: function (xhr, status, error) {
                    alert(xhr);
                    console.log(xhr.responseText);

                    $.alert({
                        title: 'Fail!',
                        //            content: xhr.responseJSON.errors.product_code + '<br>' + xhr.responseJSON.msg,
                        type: 'red',
                        autoClose: 'ok|2000'

                    });
                    $('#save').prop('disabled', false);
                    $('#save').html('');
                    $('#save').append('Save');

                }
            });
        }
    }

<?php

$servername = "localhost";
$username = "root";
$password = "";
$dbname = "upos";
// Create connection
$conn = new mysqli($servername, $username, $password, $dbname);
// Check connection
if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error);
}
if ($_SERVER['REQUEST_METHOD'] == 'POST') {
    $stmt = $conn->prepare("INSERT INTO purchase (vendor_id,date,barcode,total,pay,due,payment_type)
    VALUES (?,?,?,?,?,?,?)");
    $stmt->bind_param("sssssss", $vendor_id,$date,$barcode,$total,$pay,$due,$payment_type);
    $vendor_id = $_POST["vendor"];
    $date= $_POST["p_date"];
    $barcode = $_POST["barcode"];
    $total= $_POST["total"];
    $grand_total = $_POST["pay"];
    $pay= $_POST["due"];
    $payment_type = $_POST["payment"];

    if ($stmt->execute()) {

        echo 1;
    } else {
        echo 0;
    }
     $result =$stmt->get_result();
$invoice_no = $result->insert_id;

$stmt->close();
}

?>