using System;

using System.Windows.Forms;

using System.Data.SqlClient;

using system.data.sqlclient;ur sql address

namespace LoginForm

{

    public partial class formLogin : Form

        InitializeComponent();

        }

        private void btnLogin_Click(object sender, EventArgs e)

         sqlconnection con =new sqlconnection = @"Data Source=as ur one;Integrated Security=True; 

         sql command cmd=new sqlcommand("select from login where username='"+textuser.text+" and password='"+textpass.text+'"

            sqldataadepter sda=new SqlDataAdapter(cmd);

            data table dt=new datatable();

           sda.fill(dt);

            string cmbitemvalue=comboBox1.selecteditem.tostring()==cmbitemvalue

            {

            messegebox.show("You are login as "+dt.rows[i][2];

            if(comboBox1.selectedindex==0)

            {

            form2=new form2();

            f.show();

            this.hide();

            }

            else if (comboBox1.selectedindex==1)

            {

                form3=new form3();

            f.show();

            this.hide();

            }

            else if (comboBox1.selectedindex==2)

            {

            form4=new form4();

            f.show();

            this.hide();

            }

            else if (comboBox1.selectedindex==3)

            {

                form5=new form5();

            f.show();

            this.hide();

            }

            else  (comboBox1.selectedindex==4)

            form6 ff=new form6();

            ff.show();

            this.hide();

        {

            if (txtUserName.Text == "")

            {

                MessageBox.Show("Please enter username", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);

                txtusername.Focus(); 

                return;

            }

            if (txtPassword.Text == "")

            {

                MessageBox.Show("Please enter password", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);

                txtPassword.Focus();

                return;

            }

​

            cmd.Parameters.AddWithValue("@userid", txtUserid.Text.ToString());

            cmd.Parameters.AddWithValue("@password", txtPassword.Text.ToString());

            cmd.parameters.addwithvalue("@type",cmbox.text.tostring)();

            {

                    txtUserName.Clear();

                    txtPassword.Clear();

                    txttype.clear();

                }

                if (myConnection.State == ConnectionState.Open)

                {

                    myConnection.Dispose();

                }

        private void btnExit_Click(object sender, EventArgs e)

        {

            Application.Exit();

        }

    }

}

​