检查角色，用户名和密码，并在欢迎页面mvc5上重定向

我正在创建一个web应用程序在mvc 5在我的登录表单我有2个文本框，一个按钮还有一个span，如果用户提供了错误的信息那么文本应该是可见的

    <div style="margin-top:20px;">
        <span>
            <select style="width:275px; height:45px; font-size:15px; font-family:Verdana;" class="ddl">
                <option>Select Your Role</option>
                <option>Super Admin</option>
                <option>Admin</option>
                <option>Company</option>
                <option>Unit</option>
                <option selected="selected">Trainer</option>
                <option>Employee</option>
                <option>Partner Manager</option>
                <option>Regional Partner Manager</option>
                <option>Assistant Partner Manager</option>
                <option>Zonal Partner Manager</option>
                <option>LLT</option>
            </select>
        </span>
    </div>
<div class="col-xs-offset-0" style="margin-top:15px;">
    <span>
        <input type="text" id="txtusrname" class="ddl txtbo" style="width:275px; height:45px; font-size:15px; font-family:Verdana;" placeholder="Username" />
    </span>
</div>
<div class="col-xs-offset-0" style="margin-top:15px;">
    <span>
        <input type="text" class="ddl txtbo" id="txtpass" style="width:275px; height:45px; font-size:15px; font-family:Verdana;" placeholder="Password" />
    </span>
</div>
    <div class="imagediv" style="">
        <input id="btnerp" type="button" class="btn btn-default btnspacererp" style="" width="200" height="34" value="Login" />
    </div>
   <div class="" style="margin-top:20px; Width:auto; Height:34px; margin-left:-20px;">
   <span style="font-size:14px; visibility:hidden; font-family:Verdana; color:red;">Incorrect Login Credential!!!!</span> 
   </div>

，我从webservice传递所有登录信息，我的webservice将检查(下拉列表，用户名和密码)，如果用户提供的信息(下拉列表，用户名和密码)是正确的，那么页面应该重定向到欢迎页面，否则它应该显示span消息

[WebMethod]
    public string getlogintype(string role, string username, string password)
    {
        SqlConnection con = new SqlConnection("connectionstring");
        List<object> login = new List<object>();
    if (role == "Admin" || role == "Super Admin")
    {
        SqlCommand cmd = new SqlCommand("select * from [admin] where userid='" + username + "' and pass ='" + password + "'", con);
        con.Open();
        SqlDataAdapter da = new SqlDataAdapter(cmd);
        DataTable dt = new DataTable();
        da.Fill(dt);
        if (dt.Rows.Count > 0)
        {
            fals = null;
            tru = "true";
            //HttpContext.Current.Session["tru"] = tru.ToString();
            // want to redirect to welcome page if condition satisfied.
        }
        else
        {
            tru = null;
            fals = "false";
            //want to show the label error message(declare as string errormsg)
        }
        con.Close();
    }
    else if (role == "Company")
    {
        SqlCommand cmd = new SqlCommand("select * from companydetails where comid='" + username + "' and pass='" + password + "'", con);
        con.Open();
        SqlDataAdapter da = new SqlDataAdapter(cmd);
        DataTable dt = new DataTable();
        da.Fill(dt);
        if (dt.Rows.Count > 0)
        {
            tru = "true";
        }
        else
        {
            fals = "false";
        }
        con.Close();
    }
    else if (role == "Unit")
    {
        SqlCommand cmd = new SqlCommand("select * from companyallot where email='" + username + "' and password='" + password + "'", con);
        con.Open();
        SqlDataAdapter da = new SqlDataAdapter(cmd);
        DataTable dt = new DataTable();
        da.Fill(dt);
        if (dt.Rows.Count > 0)
        {
            tru = "true";
        }
        else
        {
            fals = "false";
        }
        con.Close();
    }
    else if (role == "Trainer")
    {
        SqlCommand cmd = new SqlCommand("select * from trainerdetails where trid='" + username + "' and pass='" + password + "'", con);
        con.Open();
        SqlDataAdapter da = new SqlDataAdapter(cmd);
        DataTable dt = new DataTable();
        da.Fill(dt);
        if (dt.Rows.Count > 0)
        {
            tru = "true";
        }
        else
        {
            fals = "false";
        }
        con.Close();
    }
    else if (role == "Employee")
    {
        SqlCommand cmd = new SqlCommand("select * from employee details where empid='" + username + "' and pass='" + password + "'", con);
        con.Open();
        SqlDataAdapter da = new SqlDataAdapter(cmd);
        DataTable dt = new DataTable();
        da.Fill(dt);
        if (dt.Rows.Count > 0)
        {
            tru = "true";
        }
        else
        {
            fals = "false";
        }
        con.Close();
    }
    else if (role == "Partner Manager")
    {
        SqlCommand cmd = new SqlCommand("select * from trainerdetails where trid='" + username + "' and pass='" + password + "'", con);
        con.Open();
        SqlDataAdapter da = new SqlDataAdapter(cmd);
        DataTable dt = new DataTable();
        SqlDataReader dr = cmd.ExecuteReader();
        while (dr.Read())
        {
            strname = dr["empname"].ToString();
        }
        con.Close();
        con.Open();
        da.Fill(dt);
        if (dt.Rows.Count > 0)
        {
            SqlCommand cmdvalid = new SqlCommand("select comname from companydetails where pm='" + strname + "'", con);
            SqlDataAdapter davalid = new SqlDataAdapter(cmdvalid);
            DataSet ds = new DataSet();
            davalid.Fill(ds);
            if (ds.Tables[0].Rows.Count != 0)
            {
                tru = "true";
            }
            else
            {
                fals = "false";
            }
        }
        con.Close();
    }
    else if (role == "Regional Partner Manager")
    {
        SqlCommand cmd = new SqlCommand("select * from trainerdetails where trid='" + username + "' and pass='" + password + "'", con);
        con.Open();
        SqlDataAdapter da = new SqlDataAdapter(cmd);
        DataTable dt = new DataTable();
        SqlDataReader dr = cmd.ExecuteReader();
        while (dr.Read())
        {
            strname = dr["empname"].ToString();
        }
        con.Close();
        con.Open();
        da.Fill(dt);
        if (dt.Rows.Count > 0)
        {
            SqlCommand cmdvalid = new SqlCommand("select trainer from rpmallot where trainer='" + strname + "'", con);
            SqlDataAdapter davalid = new SqlDataAdapter(cmdvalid);
            DataSet ds = new DataSet();
            davalid.Fill(ds);
            if (ds.Tables[0].Rows.Count != 0)
            {
                tru = "true";
            }
            else
            {
                fals = "false";
            }
        }
        con.Close();
    }
    else if (role == "Assistant Partner Manager")
    {
        SqlCommand cmd = new SqlCommand("select * from trainerdetails where trid='" + username + "' and pass='" + password + "'", con);
        con.Open();
        SqlDataAdapter da = new SqlDataAdapter(cmd);
        DataTable dt = new DataTable();
        SqlDataReader dr = cmd.ExecuteReader();
        while (dr.Read())
        {
            strname = dr["empname"].ToString();
        }
        con.Close();
        con.Open();
        da.Fill(dt);
        if (dt.Rows.Count > 0)
        {
            SqlCommand cmdvalid = new SqlCommand("select apm from companydetails where apm='" + strname + "'", con);
            SqlDataAdapter davalid = new SqlDataAdapter(cmdvalid);
            DataSet ds = new DataSet();
            davalid.Fill(ds);
            if (ds.Tables[0].Rows.Count != 0)
            {
                tru = "true";
            }
            else
            {
                fals = "false";
            }
        }
        con.Close();
    }
    else if (role == "Zonal Partner Manager")
    {
        SqlCommand cmd = new SqlCommand("select * from trainerdetails where trid='" + username + "' and pass='" + password + "'", con);
        con.Open();
        SqlDataAdapter da = new SqlDataAdapter(cmd);
        DataTable dt = new DataTable();
        SqlDataReader dr = cmd.ExecuteReader();
        while (dr.Read())
        {
            strname = dr["empname"].ToString();
        }
        con.Close();
        con.Open();
        da.Fill(dt);
        if (dt.Rows.Count > 0)
        {
            SqlCommand cmdvalid = new SqlCommand("select trainer from zonerpm where trainer='" + strname + "'", con);
            SqlDataAdapter davalid = new SqlDataAdapter(cmdvalid);
            DataSet ds = new DataSet();
            davalid.Fill(ds);
            if (ds.Tables[0].Rows.Count != 0)
            {
                tru = "true";
            }
            else
            {
                fals = "false";
            }
        }
        con.Close();
    }
    else if (role == "LLT")
    {
        SqlCommand cmd = new SqlCommand("select * from trainerdetails where trid='" + username + "' and pass='" + password + "' and type='" + role + "'", con);
        con.Open();
        SqlDataAdapter da = new SqlDataAdapter();
        DataTable dt = new DataTable();
        da.Fill(dt);
        if (dt.Rows.Count > 0)
        {
            tru = "true";
        }
        else
        {
            fals = "false";
        }
        con.Close();
    }
    string finalreturn = "";
    if(fals=="false")
    {
        finalreturn = fals.ToString();
    }
    else if(tru=="true")
    {
        finalreturn = tru.ToString();
    }
    return finalreturn.ToString();
}

}

如果用户信息为真，此web服务将返回真;如果提供的用户名、密码或角色为假，则该信息将传递到操作结果页面，其中我有三个字符串(用户名、密码、角色)我想在会话中获取他的所有登录信息，并将用户重定向到欢迎页面

public ActionResult Login(string role, string username, string password)
{
    //required code
}

这是我的actionresult，我需要在这里传递它来验证并重定向到欢迎页面