function funkcja1()
{
    // cos sie tu robi
    funkcja2();
}

function funkcja2()
{
    // cos tu sie robi
}

function handleServerNpfResult()
{
    // move forward only if the transaction has completed
    if (xmlHttp.readyState == 4)
    {
        // status of 200 indicates the transaction completed successfully
        if (xmlHttp.status == 200)
        {
            responseXml = xmlHttp.responseXML;
            xmlDoc = responseXml.documentElement;
            
            if ( xmlDoc.getElementsByTagName("npf")[0] )
            {    
                npf = xmlDoc.getElementsByTagName("npf")[0].firstChild.data;
                document.codecalcform.npf.value = npf;
                NPF = npf;
                calculatePF();
                // restart sequence
                setTimeout('handleServerNpfResult()', 1000);
            }
        }
        // a HTTP status different than 200 signals an error
        else
        {
            alert("There was a problem accessing the server: " + xmlHttp.statusText);
        }
    }
}

// move forward only if the transaction has completed
    if (xmlHttp.readyState == 4)
    {...

// stores the reference to the XMLHttpRequest object
var xmlHttp = createXmlHttpRequestObject();
// retrieves the XMLHttpRequest object
function createXmlHttpRequestObject()
{
    // will store the reference to the XMLHttpRequest object
    var xmlHttp;
    // if running Internet Explorer
    if(window.ActiveXObject)
    {
        try
        {
            xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
        }
        catch (e)
        {
            xmlHttp = false;
        }
    }
    // if running Mozilla or other browsers
    else
    {
        try
        {
            xmlHttp = new XMLHttpRequest();
        }
        catch (e)
        {
            xmlHttp = false;
        }
    }
    // return the created object or display an error message
    if (!xmlHttp)
        alert("Error creating the XMLHttpRequest object.");
    else
        return xmlHttp;
}