var XMLHttpRequestObject = false;

if (window.XMLHttpRequest){
  XMLHttpRequestObject = new XMLHttpRequest();
}
else if (window.ActiveXObject){
  XMLHttpRequestObject = new ActiveXObject("Microsoft.XMLHTTP");
}


 function sprawdz_kontakt(form){
	
	if (form.tresc.value==""){
		window.alert("Prosze podac tresc zapytania!");
		form.tresc.focus();
		return false;
	}
	else if (form.email.value==""){
		window.alert("Prosze podac email!");
		form.email.focus();
		return false;
	}
	else{
		if(XMLHttpRequestObject){
    		var div = document.getElementById('komunikat');
		    var url = "form_kontaktu.php";
		    XMLHttpRequestObject.open("POST", url);
		    XMLHttpRequestObject.setRequestHeader(
		      'Content-Type', 'application/x-www-form-urlencoded');
		    XMLHttpRequestObject.onreadystatechange = function()
    		{
      			if(XMLHttpRequestObject.readyState == 4 && 
          			XMLHttpRequestObject.status == 200){
        			var str = XMLHttpRequestObject.responseText;
        			div.innerHTML = str;
      }
    }
    XMLHttpRequestObject.send("tresc=" + form.tresc.value + "& email=" + form.email.value );
	
	}	

}
 }