function check_if_free()
{
	var subdomain =document.registration_form.subdomain.value;
      var fields = new Array();
   
   
    var sendf = 'subdomain='+subdomain;

	xmlhttp.open("POST",'/is_it_free_server.php',true);

		

	xmlhttp.setRequestHeader("Content-Type","application/x-www-form-urlencoded; charset=UTF-8");
	xmlhttp.send(sendf);



	xmlhttp.onreadystatechange = function() 
	{
		if (xmlhttp.readyState == 4 && xmlhttp.status == 200) 
		{
			var str = xmlhttp.responseText;	
		     var elem = document.getElementById("check_if_free");
			elem.innerHTML = str;

		}
	}
}