How to call a class into aspx.cs

Hi all this the class that what i have created. Plase i want it to call into my aspx.cs web form. How can i do that? I tried namespace.login; it dosen't work.

And i want to know how to call this class into the aspx.cs form.

 

Thank you. 

 

 

 

using System;

using System.Collections.Generic;

using System.Data.SqlClient;

using System.Data;

using System.Linq;

using System.Web;

namespace Food_Calorie_Calculator__Final_Project.Account

{

public class Login

{

static string U_EmailAddress;

static string U_Password;

public string ID = string.Empty;

SqlConnection conn = Main.GetDBConnection();

public Login()

{ }

public Login(string _U_EmailAddress, string _U_Password)

{

U_EmailAddress = _U_EmailAddress;

U_Password = _U_Password;

}

public string getemailinfo

{

get

{

return U_EmailAddress;

}

}

public string getpassinfo

{

get

{

return U_Password;

}

}

public string Validation()

{

try

{

DataTable usertable = new DataTable();

string SQL = @"SELECT U_EmailAddress FROM User_tb where

U_EmailAddress ='" + U_EmailAddress + "' AND U_Password ='" + U_Password + "'";

SqlDataAdapter Userdataadapter = new SqlDataAdapter(SQL, conn);

Userdataadapter.Fill(usertable);

foreach (DataRow myrow in usertable.Rows)

{

ID = (myrow[0].ToString());

}

}

catch (InvalidCastException e)

{

throw (e); // Rethrowing exception e

}

return ID;

}

}

}