//get latitude and longitude from ui
    latitude = ui->latitude->toPlainText().toDouble();
    longitude = ui->longitude->toPlainText().toDouble();

    //query to get latitude, longitude and template from way_point table in database
    QSqlQuery query1;
    query1.exec("SELECT w, latitude, longitude, template FROM way_point ORDER BY template ASC;");

    //get smallest distance from ui latitude longitude and latitude longitude in database
    double start = 1000000;
    double tmp;
    int template_way, index;
    while (query1.next()){
        tmp = distance_two_point(latitude,longitude,query1.value(1).toDouble(),query1.value(2).toDouble());
        if(start > tmp){
            start = tmp;
            template_way = query1.value(3).toInt();
            index = query1.value(0).toInt();
        }
    }

    //query to get value from two point in database
    QList<double> result;
    QSqlQuery query2;
    query2.prepare(("SELECT r FROM line WHERE template = ? ORDER BY w1 ASC;"));
    query2.addBindValue(template_way);
    query2.exec();
    while (query2.next()) {
        result.append(query2.value(0).toDouble());
    }

    //if template not found in database
    if(result.isEmpty()){
        ui->textEdit->setText("Template not Found");
    } else{

        //get distance from ui latitude longitude to destination point in database
        double sum = start;
        for(int i=index-2;i >= 0;i--){
            sum = sum + result[i];
        }

        //show distance value in KM
        ui->textEdit->setText(QString::number(sum) + " KM to template " + QString::number(template_way));