C#

public Hashtable staffTable;

public FrmMain()
{
    InitializeComponent();
    staffTable = new Hashtable();
}

private FrmMain ParentForm;
private Staff staff;

public FrmLogin()
{
    InitializeComponent();

    staff = new Staff("Admin", "S123456A", "pass123", "13 April 1988", "ADDRESS", 912346678, 12345678, true, true, false, true);
    ((FrmMain)ParentForm).staffTable.Add("S8812466I", staff);
}

using System;
using System.Windows.Forms;

namespace EventSample
{
    public partial class frmMain : Form
    {
        public frmMain()
        {
            InitializeComponent();
        }

        private void frmMain_Shown(object sender, EventArgs e)
        {
            frmLogin loginForm = new frmLogin();
            loginForm.StaffLogin += new OnStaffLogin(loginForm_StaffLogin);
            loginForm.ShowDialog();
            loginForm.Dispose();
        }

        void loginForm_StaffLogin(object sender, LogInEventArgs e)
        {
            MessageBox.Show("Staff logged in: " + e.Staff.Name);
        }
    }
    public class Staff
    {
        private string m_Name;
        public string Name
        {
            get { return m_Name; }
            set { m_Name = value; }
        }
        public Staff(string name)
        {
            m_Name = name;
        }
    }
}

using System;
using System.Windows.Forms;

namespace EventSample
{
    public delegate void OnStaffLogin(object sender, LogInEventArgs e);
    public partial class frmLogin : Form
    {
        public event OnStaffLogin StaffLogin;
        public frmLogin()
        {
            InitializeComponent();
        }
        private void FireStaffLogin()
        {
            StaffLogin(this, new LogInEventArgs(new Staff("Staff name goes here!")));
        }

        private void button1_Click(object sender, EventArgs e)
        {
            if (StaffLogin != null)
            {
                FireStaffLogin();
            }
            Close();
        }
    }
    public class LogInEventArgs : EventArgs
    {
        private Staff m_Staff;
        public Staff Staff
        {
            get { return m_Staff; }
            set { m_Staff = value; }
        }
        public LogInEventArgs(Staff staff)
        {
            m_Staff = staff;
        }
    }
}

namespace EBMS
{
    public partial class FrmMain : Form
    {
        public Hashtable staffTable;

        public FrmMain()
        {
            InitializeComponent();
            staffTable = new Hashtable();
        }
        private void FrmMain_Load(object sender, EventArgs e)
        {
            
            this.toolStripStaff.Visible = false;
            this.toolStripCatalogue.Visible = false;
            this.toolStripOrder.Visible = false;
            this.toolStripInventory.Visible = false;
            this.toolStrip.Enabled = false; 
            FrmLogin childLogin = new FrmLogin();
            childLogin.ShowDialog(this);
            if (childLogin.DialogResult == DialogResult.OK)
            {
                this.toolStripStaff.Visible = true;
                this.toolStripCatalogue.Visible = true;
                this.toolStripOrder.Visible = true;
                this.toolStripInventory.Visible = true;
                this.toolStripLogin.Visible = false;
                this.toolStrip.Enabled = true; 
                stripLblLoginAs.Text = "Login As : " + childLogin.Username;
            }
            
        }

namespace EBMS
{
    public partial class FrmLogin : Form
    {
        public FrmMain ParentForm;
        private Staff staff;

        public FrmLogin()
        {
            InitializeComponent();
            staff = new Staff("Admin", "S123456I", "pass123", "13 April 1988", "address", 12345678, 12346567, true, true, false, true);
            ((FrmMain)ParentForm).staffTable.Add("S123456I", staff);
        }

using System;
using System.Collections.Generic;
using System.Text;

namespace EBMS
{
    public class Staff
    {
        private string name;
        private string nric;
        private string password;
        private string dob;
        private string address;
        private uint mobile;
        private uint home;
        private bool catManager;
        private bool inventManager;
        private bool orderManager;
        private bool administrator;

        public Staff(string name, string nric, string password, string dob,
                    string address, uint mobile, uint home, bool catManager, bool inventManager,
                    bool orderManager, bool administrator)
        {
            this.name = name;
            this.nric = nric;
            this.password = password;
            this.dob = dob;
            this.address = address;
            this.mobile = mobile;
            this.home = home;
            this.catManager = catManager;
            this.inventManager = inventManager;
            this.orderManager = orderManager;
            this.administrator = administrator;
        }

        public string Name
        {
            get { return name; }
        }
        public string NRIC
        {
            get { return nric; }
        }
        public string Password
        {
            get { return password; }
        }
        public string DOB
        {
            get { return dob; }
        }

        public string Address
        {
            get { return address; }
        }
        public uint Mobile
        {
            get { return mobile; }
        }
        public uint Home
        {
            get { return home; }
        }
        public bool CatManager
        {
            get { return catManager; }
        }
        public bool InventManager
        {
            get { return inventManager; }
        }
        public bool OrderManager
        {
            get { return orderManager; }
        }
        public bool Administrator
        {
            get { return administrator; }
        }
    }
}

private Hashtable staffTableFromMain;
public FrmLogin(Hashtable staffTable)
{
    InitializeComponent();
    staffTableFromMain = staffTable;
}

benjamin yap wrote:

why cant i just cast it to mainform then get the staffTable from there? thought it should work?

namespace EBMS
{
    public partial class FrmMain : Form
    {
        public Hashtable staffTable;
        public FrmMain()
        {
            InitializeComponent();
            staffTable = new Hashtable();
        }

        private void frmMain_Load(object sender, EventArgs e)
        {
            FrmLogin childLogin = new FrmLogin();
            childLogin.StaffChange += new OnStaffChange(childLogin_StaffChange);
            childLogin.ShowDialog(this);
            childLogin.Dispose();
        }

        void childLogin_StaffChange(object sender, StaffChangeEventArgs e)
        {
            staffTable.Add(e.Staff.NRIC, e.Staff);
            MessageBox.Show("Added " + e.Staff.NRIC + " to table.");
        }
    }
}

namespace EBMS
{
    public delegate void OnStaffChange(object sender, StaffChangeEventArgs e);
    public partial class FrmLogin : Form
    {
        public event OnStaffChange StaffChange;
        public FrmLogin()
        {
            InitializeComponent();
        }
        private void FireStaffChange(Staff staff)
        {
            if (StaffChange != null)
            {
                StaffChange(this, new StaffChangeEventArgs(staff));
            }
        }

        private void button1_Click(object sender, EventArgs e)
        {
            Staff staff = new Staff(
                "Admin",
                "S123456I",
                "pass123",
                "13 April 1988",
                "address",
                12345678,
                12346567,
                true,
                true,
                false,
                true);
            FireStaffChange(staff);
            Close();
        }
    }
}

namespace EBMS
{
    public class StaffChangeEventArgs : EventArgs
    {
        private Staff m_Staff;
        public Staff Staff
        {
            get { return m_Staff; }
            set { m_Staff = value; }
        }
        public StaffChangeEventArgs(Staff staff)
        {
            m_Staff = staff;
        }
    }
}

namespace EBMS{    
public class StaffChangeEventArgs : EventArgs
    {
        private Staff m_Staff;
        public Staff Staff
        {
            get { return m_Staff; }
            set { m_Staff = value; }
        }
        public StaffChangeEventArgs(Staff staff)
        {
            m_Staff = staff;
        }
    }
}

public static Hashtable staffTable;
public static Hashtable productTable;
public static Hashtable orderTable;

public AllData()
{
staffTable = new Hashtable();
productTable = new Hashtable();
orderTable = new Hashtable();
}

public AllData allData;

public FrmMain()
{
allData = new AllData();
}

public static class AllData
{
    public static Hashtable staffTable = new Hashtable();
    public static Hashtable productTable = new Hashtable();
    public static Hashtable productTable = new Hashtable();
}

byte* p = (byte *)(void *)pBuffer;
p += (x + y * Width) * 3;
byte r = *(p++);
byte g = *(p++);
byte b = *p;