login form user status problem

Question

here is the coding of my form: using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Text; using System.Windows.Forms; using System.Configuration; using System.Data.OleDb; namespace Project { public partial class frmlogin : Form { int UserId; int UserStatus; string UserName; string UserRole; string Password; string ConfirmPassword; public frmlogin() { InitializeComponent(); } private void frmlogin_Load(object sender, EventArgs e) { } private void btnlogin_Click(object sender, EventArgs e) { try { ConnectionClass l_ConnectionClass = new ConnectionClass(); DataSet l_UserDataSet = l_ConnectionClass.FetchDataInDataSet("select * from tbluserlogin where userName = '"+txtusername.Text.ToLower().Trim()+"' and userPwd = '"+txtpwd.Text.Trim()+"'"); if (l_UserDataSet.Tables[0].Rows.Count > 0) { PublicVariables.CheckLoginFlag = true; PublicVariables.OSUserID = Convert.ToInt16(l_UserDataSet.Tables[0].Rows[0]["userId"]); PublicVariables.UserRole = l_UserDataSet.Tables[0].Rows[0]["userRole"].ToString(); Close(); } else { MessageBox.Show("Login Failed !!!!", "Error", MessageBoxButtons.OK); PublicVariables.CheckLoginFlag = false; txtusername.Text = ""; txtpwd.Text = ""; txtusername.Focus(); } } catch (Exception Ex) { MessageBox.Show("Connection Failed. Plz Check your Network Cable Connection", "Error", MessageBoxButtons.OK); } } private void btncancel_Click(object sender, EventArgs e) { this.Close(); } } } and for this i have made a connectionclass.cs form for the connection. in that only i have define publicvariables. public sealed class PublicVariables { public static Boolean CheckLoginFlag = false; public static short OSUserID = 0; public static string UserRole = ""; } now i have to set the user status in this form. like when user will login the userstatus column in the table will be updated to 1 in that user name row. and when the user will log out from the MDI form Logout or Exit strip the user status will be 0. plz help.