private void dlt_all_Click(object sender, EventArgs e)
 {
     DatabaseHelperClass Db_Helper = new DatabaseHelperClass();
     Db_Helper.DeleteAllContact();//delete all DB contacts
     DB_ContactList.Clear();//Clear collections
     lst_contacts.ItemsSource = DB_ContactList;
 }
 private async void save_Click(object sender, EventArgs e)
 {
     DatabaseHelperClass Db_helper = new DatabaseHelperClass();
     if (txt_name.Text != "" & txt_email.Text != "" & txt_number.Text != "" & txt_location.Text != "")
     { 
         Db_helper.Insert(new Contacts(txt_name.Text,txt_email.Text,txt_number.Text,txt_location.Text));
         MessageBox.Show("Contact saved", "Success :)", MessageBoxButton.OK);
         ResetAll();
     }
     else
     {
         MessageBox.Show("Fill all the fields","Error :(",MessageBoxButton.OK);
     }
 }