A Task Management System using Three Layer Architecture

using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;

/// <summary>
/// Summary description for EmployeeBLL
/// </summary>
public class EmployeeBLL
{
	public EmployeeBLL()
	{
		//
		// TODO: Add constructor logic here
		//
	}
    public string AddNewEmployee(Employee employeeObj)
    {
         EmployeeGateway employeeGateWayObj = new EmployeeGateway();
         return employeeGateWayObj.InsertEmployee(employeeObj);
    }
    public DataTable SelectUserId()
    {
        EmployeeGateway employeeGateWayObj = new EmployeeGateway();
        return employeeGateWayObj.SelectAllUserId();
    }

    public DataTable SelectAdminId()
    {
        EmployeeGateway employeeGateWayObj = new EmployeeGateway();
        return employeeGateWayObj.SelectAllAdminId();
    }
    public DataTable SelectLoginRole(int index)
    {
        EmployeeGateway employeeGatewayObj = new EmployeeGateway();
        DataTable dt = new DataTable();
        switch (index)
        {
            case 0:
                dt = employeeGatewayObj.SelectAllAdminId();
                
                break;
            case 1:
                dt = employeeGatewayObj.SelectAllUserId();
                
                break;
                
        }
        return dt;
    }
    public void CreateAdmin(string userId)
    {
        EmployeeGateway employeeGateWayObj = new EmployeeGateway();
        employeeGateWayObj.CreateAdmin(userId);
    }
    public void CreateUser(string employeeId, string password)
    {
        EmployeeGateway employeeGateWayObj = new EmployeeGateway();
        employeeGateWayObj.CreateUser(employeeId, password);
    }
    public DataTable SelectAllEmployeeBasicInformation()
    {
        EmployeeGateway employeeGateWayObj = new EmployeeGateway();
        return employeeGateWayObj.SelectAllEmployeeData();
    }
    public string RemoveAdmin(string adminId)
    {
        EmployeeGateway employeeGateWayObj = new EmployeeGateway();
        ProjectGateway projectGateWayObj = new ProjectGateway();
        TaskGateWay taskGateWayObj = new TaskGateWay();

        if ((projectGateWayObj.CountRunningProjectOfUser(adminId) > 0) || (taskGateWayObj.CountRunningTaskOfUser(adminId) > 0))
        {
            return "The User is under running Project.";
        }
        else
        {

            employeeGateWayObj.RemoveAdmin(adminId);
            return "The Admin is removed";
        }
    }
    public string RemoveUser(string userId)
    {
        EmployeeGateway employeeGateWayObj = new EmployeeGateway();
        ProjectGateway projectGateWayObj = new ProjectGateway();
        TaskGateWay taskGateWayObj = new TaskGateWay();

        if ((projectGateWayObj.CountRunningProjectOfUser(userId) > 0) || (taskGateWayObj.CountRunningTaskOfUser(userId) > 0))
        {
            return "The User is under running Project.";
        }

        else
        {
            employeeGateWayObj.RemoveUser(userId);
            return "The User is removed";
        }
    }
    public DataTable SelectAllAdminData()
    {
        EmployeeGateway employeeObj = new EmployeeGateway();
        return employeeObj.SelectAllAdminData();
    }
    public DataTable SelectAllEmployeeId()
    {
        EmployeeGateway employeeObj = new EmployeeGateway();
        return employeeObj.SelectAllEmployeeId();
    }
    public DataTable SelectAllUserData()
    {
        EmployeeGateway employeeObj = new EmployeeGateway();
        return employeeObj.SelectAllUserData(); ;
    }


}