how to call a logic in model using controller in ASP.NET c# MVC? HELP!?

[Pam L]

This is my logic code in the Model


public class Database
{
private string UsernameInDatabase = "pamilee";
private string PasswordInDatabase = "abcd";
private string RoleInDatabase = "Developer";

public string Validate(string username, string password, string role)
{

string success = UsernameInDatabase;

try
{
if (username == UsernameInDatabase && password == PasswordInDatabase)
{
success = "WELCOME " + UsernameInDatabase + "!";

}
else
{
success = "LOGIN FAILED!";
}


}
catch (Exception e)
{
success = e.Message;
}
finally
{

}
return success;
}

}

Please help me =(