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


namespace Trial
{ 
    public partial class Form1 : Form

    {

        private int _attempts;
        public static string user;



        public Form1()
        {
            InitializeComponent();
            tbuser.Text = user;
        }


        private void bexit_Click(object sender, EventArgs e)
        {
            this.Close();
            MDIParent1 mp = new MDIParent1();
            mp.Close();
        }



        public void blogin_Click(object sender, EventArgs e)
        {

            SqlConnection sc = new SqlConnection(@"Data Source=(LocalDB)\v11.0;AttachDbFilename=C:\Users\Marc\Documents\Trial.mdf;Integrated Security=True;Connect Timeout=30");
            SqlDataAdapter sda = new SqlDataAdapter("Select ROLE From login where username = '"+ tbuser.Text +"' and password = '"+ tbpass.Text +"'", sc);
            DataTable dt = new System.Data.DataTable();


            sda.Fill(dt);
            if (dt.Rows.Count == 1)
            {
                _attempts = 0;
                this.Hide();
                MDIParent1 mp = new MDIParent1(dt.Rows[0][0].ToString());
                mp.Show();
                // ((Form)ss).Controls["label1"].Text = dt.Rows[0][0].ToString();
            }
            else
            {
                MessageBox.Show("Invalid Username or Password");
                _attempts++;
            }
            if (_attempts == 3) this.Close();
        }

        private void Form1_Load(object sender, EventArgs e)
        {

        }

        private void lpassword_Click(object sender, EventArgs e)
        {

        }

        private void Form1_Load_1(object sender, EventArgs e)
        {

        }

        private void tbuser_TextChanged(object sender, EventArgs e)
        {

        }
    }
}


MDIParent Form :

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

namespace Trial
{
    public partial class MDIParent1 : Form
    {


        public MDIParent1(string role)
        {
            InitializeComponent();
            label1.Text = role;
        }
        SqlConnection scon = new SqlConnection(@"Data Source=(LocalDB)\v11.0;AttachDbFilename=C:\Users\Marc\Documents\Trial.mdf;Integrated Security=True;Connect Timeout=30");

        public MDIParent1()
        {
            // TODO: Complete member initialization
        }

        private void mainWindowToolStripMenuItem_Click(object sender, EventArgs e)
        {

            mainwindow mw = new mainwindow();
            mw.MdiParent = this;
            mw.Show();


        }

        private void label1_Click(object sender, EventArgs e)
        {

        }

        private void MDIParent1_Load(object sender, EventArgs e)
        {


        }

        private void openToolStripMenuItem_Click(object sender, EventArgs e)
        {

        }

        private void menuStrip_ItemClicked(object sender, ToolStripItemClickedEventArgs e)
        {

        }

        private void updateEmployeeToolStripMenuItem_Click(object sender, EventArgs e)
        {

        }

        private void addEmployeeToolStripMenuItem_Click(object sender, EventArgs e)
        {
            EMPLOYEE addemp = new EMPLOYEE();
            addemp.MdiParent = this;
            addemp.Show();

        }

        private void searchEmployeeToolStripMenuItem_Click(object sender, EventArgs e)
        {
            EMPLOYEE2 srchemp = new EMPLOYEE2();
            srchemp.MdiParent = this;
            srchemp.Show();
        }

        private void employeeReportsToolStripMenuItem_Click(object sender, EventArgs e)
        {
            REPORT report = new REPORT();
            report.MdiParent = this;
            report.Show();
        }

        private void changePasswordToolStripMenuItem_Click(object sender, EventArgs e)
        {
            SETTINGS settings = new SETTINGS();
            settings.MdiParent = this;
            settings.Show();
        }

        private void sts_Click(object sender, EventArgs e)
        {

        }

        private void toolStripStatusLabel_Click(object sender, EventArgs e)
        {

        }


    }
}