using UnityEngine;
using System.Collections;
using UnityEngine.UI;

public class UIManager : MonoBehaviour
{
    public InputField output;

    public void SaveStrOnClick()
    {
        StartCoroutine("SaveStr");
    }

    IEnumerator SaveStr()
    {
        WWWForm form = new WWWForm();
        form.AddField("str", "Hello");
        WWW www = new WWW("http://dev3dapps.freeoda.com/unity/Polyglot/database.php", form);
        yield return www;
        output.text = www.text;
    }
}

<?php

if (!empty($_POST["str"]))
{
    $str = $_POST["str"];
    echo "Ok, we get: ".$str;
}
else
{
   echo "Error: cannot get str";
}

<?php

header("Access-Control-Allow-Credentials: true");
header('Access-Control-Allow-Headers: Accept, X-Access-Token, X-Application-Name, X-Request-Sent-Time');
header('Access-Control-Allow-Methods: POST, GET, OPTIONS');
header('Access-Control-Allow-Origin: *');

if (!empty($_POST["str"]))
{
    $str = $_POST["str"];
    echo "Ok, we get: ".$str;
}
else
{
   echo "Error: cannot get str";
}

using UnityEngine;
using System.Collections;
using UnityEngine.UI;
using System.Collections.Generic;

public class UIManager : MonoBehaviour
{
    public InputField output;

    public void SaveStrOnClick()
    {
        StartCoroutine("SaveStr");
    }

    IEnumerator SaveStr()
    {
        WWWForm form = new WWWForm();

        form.headers.Add("Access-Control-Allow-Credentials", "true");
        form.headers.Add("Access-Control-Allow-Headers", "Accept");
        form.headers.Add("Access-Control-Allow-Methods", "POST");
        form.headers.Add("Access-Control-Allow-Origin", "*");
        form.AddField("str", "Hello");

        WWW www = new WWW("http://dev3dapps.freeoda.com/unity/Polyglot/database.php", form);
        yield return www;

        try
        {
            output.text = www.text;
        }
        catch (System.Exception)
        {
            output.text = "Error in: output.text = www.text;";
        }
    }
}

using UnityEngine;
using System.Collections;
using UnityEngine.UI;

public class UIManager : MonoBehaviour
{
    public InputField output;

    public void SaveStrOnClick()
    {
        StartCoroutine("SaveStr");
    }

    IEnumerator SaveStr()
    {
        WWWForm form = new WWWForm();
        form.AddField("str", "Hello");
        WWW www = new WWW("http://dev3dapps.freeoda.com/unity/Polyglot/database.php", form);
        yield return www;
        output.text = www.text;
    }
}

<?php

header("Access-Control-Allow-Credentials: true");
header('Access-Control-Allow-Origin: *');
header('Access-Control-Allow-Methods: POST, GET, OPTIONS');
header('Access-Control-Allow-Headers: Accept, X-Access-Token, X-Application-Name, X-Request-Sent-Time');

if (!empty($_POST["str"]))
{
    $str = $_POST["str"];
    echo "Ok, we get: ".$str;
}
else
{
   echo "Error: cannot get str";
}

using UnityEngine;
using System.Collections;
using UnityEngine.UI;

public class Login : MonoBehaviour
{
    public InputField output;

    public void OnClick_Login()
    {
        StartCoroutine("SendName");
    }

    IEnumerator SendName()
    {
        WWWForm form = new WWWForm();
        form.AddField("name", "Ivan");
        WWW www = new WWW("http://qtobserver.somee.com/*********.aspx", form);
        yield return www;
        output.text = www.text;
    }
}

        protected void Page_Load(object sender, EventArgs e)
        {
            string name = Request.Form["name"];
            Response.Write("Hello " + name);
        }