C#

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Collections;

namespace WindowsFormsApplication1
{



    public partial class Form1 : Form
    {
        ArrayList vins = new ArrayList();

        public Form1()
        {
            InitializeComponent();
        }

        public void CreateDataTable()
        {
            string s1 = "Date";
            string s2 = "System.String";
            DataTable dt = new DataTable();
            dt.TableName = textBox1.Text;

            while (s1!= "Stop")
            {   
                DataColumn dc = new DataColumn();
                dc.ColumnName = s1;
                dc.Caption = dc.ColumnName;
                dc.DataType = System.Type.GetType(s2);
                dc.DefaultValue = null;
                dt.Columns.Add(dc);

                switch (s1)
                {
                    case "Date":
                        s1 = "Member#";
                        s2 = "System.Int32";
                        break;
                    case "Member#":
                        s1 = "VIN#";
                        s2 = "System.Int32";
                        break;
                    case "VIN#":
                        s1 = "Location Name";
                        s2 = "System.String";
                        break;
                    case "Location Name":
                        s1 = "Address";
                        s2 = "System.String";
                        break;
                    case "Address":
                        s1 = "City";
                        s2 = "System.String";
                        break;
                    case "City":
                        s1 = "State";
                        s2 = "System.String";
                        break;
                    case "State":
                        s1 = "Zip";
                        s2 = "System.Int32";
                        break;
                    case "Zip":
                        s1 = "Phone";
                        s2 = "System.String";
                        break;
                    case "Phone":
                        s1 = "Fax";
                        s2 = "System.String";
                        break;
                    case "Fax":
                        s1 = "Email";
                        s2 = "System.String";
                        break;
                    case "Email":
                        s1 = "Stop";
                        break;
                }
            }
            DataRow dr;
            dr = CreateTableRow(dt);
        }

        public DataRow CreateTableRow(DataTable dtPass)
        {
            // Check VIN against DataTable
            DataRow myRow;
            myRow = dtPass.NewRow();
            DateTime today = DateTime.Now;
            string date;
            int year = today.Year;
            int month = today.Month;
            int day = today.Day;
            date = month + "\\" + day + "\\" + year;
            // From Form1
            myRow[0] = date;
            myRow[1] = int.Parse(textBox1.Text);
            myRow[2] = int.Parse(textBox2.Text); // Change to a while statement to add all vins in ArrayList and also call the VIN checking function
            
            // From Form2
            //dr[3] = 
            return myRow;
        }

        private void label1_Click(object sender, EventArgs e)
        {

        }

        private void AddTruck()
        {
            try
            {
                if (textBox2.Text != null)
                {
                    long vinNumber = long.Parse(textBox2.Text);
                    vins.Add(vinNumber);
                    textBox2.Text = "";
                    label3.Text = label3.Text + vinNumber + Environment.NewLine;
                }
            }
            catch (FormatException)
            {
                textBox2.Text = "";
            }
        }

        private void button1_Click(object sender, EventArgs e)
        {
            Form2 f = new Form2(this);
            //f.Show();   // This shows Form2

            AddTruck();
            // CheckforDuplicateVin();

            /* 
             * Check DB for Member#
             * Check DB for duplicate VIN#
             * 
             * If Member#.!Exist && !duplicateVin
             * {
             *      Create DataTable for new member
             *      Open a form to fill in the location information
             *      Open the new DataTable
             *      Save the DataTable to the DataSheet/Database
             * }
             * Elseif Member#.Exist && !duplicateVin
             * {
             *      Open DataTabel for current member
             *      Add new VIN to the DataSheet/Database
             * }
             * Else
             * {
             *      Output duplicate VIN error message
             * }
            */
        }

        private void OpenContactInfo()
        {
            //Open form 2
        }
        private void button2_Click(object sender, EventArgs e)
        {
            /* Check DB for an existing member
             * If No, open Form2
             * If Yes, Pull data from Data Table
             * Do not open Form2
             * Possibly open a Form for confirmation 
            */

            // Check ArrayList vin vs DB for a duplicate

            // Edit the line below so that it only runs if the member is new
            
            // If !ExistingMember
            //{A
            try // Edit this so that it catches non numerical character entry
            {
                if (textBox1.Text != null)
                {
                    
                    CreateDataTable();
                    // Call OpenContactInfo
                }
            }
            catch (FormatException)
            {
                textBox1.Text = "";
            }
            //}A


        }
    }
}

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace WindowsFormsApplication1
{
    public partial class Form2 : Form
    {
        Form1 f;

        public Form2()
        {
            InitializeComponent();
        }

        public Form2(Form1 fr1)
        {
            InitializeComponent();
            f = new Form1();
            f = fr1;

        }

        private void Form2_Load(object sender, EventArgs e)
        {

        }
    }
}

NpgsqlDataAdapter da = new NpgsqlDataAdapter(com);
            DataTable dt = new DataTable();
            BindingSource bs = new BindingSource();
            da.Fill(dt);
            bs.DataSource = dt;
            if(dt.Rows.Count != 0)
            {
                qDesigner.dgvFilters.AutoGenerateColumns = false;
                qDesigner.dgvFilters.DataSource = bs;
                qDesigner.dgvFilters.Columns["dgvColTable"].DataPropertyName = dt.Columns[0].ColumnName;
                //qDesigner.dgvFilters.Columns["dgvColColumn"].DataPropertyName = dt.Columns["Column"].ColumnName;
                //qDesigner.dgvFilters.Columns["dgvColSort"].DataPropertyName = dt.Columns["Sort"].ColumnName;
                qDesigner.dgvFilters.Columns["dgvColCriteria"].DataPropertyName = dt.Columns["Criteria"].ColumnName;
                qDesigner.dgvFilters.Columns["dgvColOr1"].DataPropertyName = dt.Columns["ColOr1"].ColumnName;
                qDesigner.dgvFilters.Columns["dgvColOr2"].DataPropertyName = dt.Columns["ColOr2"].ColumnName;
            }