malá úprava ajaxu

/*
* @copyright Jakub Vrána, http://php.vrana.cz
*/
function send_xmlhttprequest(state_change, method, url, content, headers) {
    var xmlhttp = (window.XMLHttpRequest ? new XMLHttpRequest() : (window.ActiveXObject ? new ActiveXObject("Microsoft.XMLHTTP") : false));
    if (!xmlhttp) {
        return false;
    }
    xmlhttp.open(method, url);
    xmlhttp.onreadystatechange = function () {
        state_change(xmlhttp);
    };
    headers = headers || {};
    headers['X-Requested-With'] = headers['X-Requested-With'] || 'XMLHttpRequest';
    for (var key in headers) {
        xmlhttp.setRequestHeader(key, headers[key]);
    }
    xmlhttp.send(content);
    return true;
}

function post_xmlhttprequest(state_change, url, form, headers) {
    var elements = form.elements;
    var content = [];
    for (var i=0; i < elements.length; i++) {
        if (elements[i].attributes.name && elements[i].attributes.name.specified && !elements[i].disabled) {
            if (/^(select)$/i.test(elements[i].tagName)) {
                var options = elements[i].options;
                for (var j=0; j < options.length; j++) {
                    if (options[j].selected) {
                        var value = (options[j].attributes.value && options[j].attributes.value.specified ? options[j].value : options[j].text);
                        content.push(encodeURIComponent(elements[i].name) + '=' + encodeURIComponent(value));
                    }
                }
            } else if (!/^(submit|reset|button|file|image)$/i.test(elements[i].type) && (!/^(radio|checkbox)$/i.test(elements[i].type) || elements[i].checked)) {
                content.push(encodeURIComponent(elements[i].name) + '=' + encodeURIComponent(elements[i].value));
            }
        }
    }
    if (!headers) {
        headers = {};
    }
    headers['Content-Type'] = 'application/x-www-form-urlencoded';
    return send_xmlhttprequest(state_change, 'POST', url, content.join('&'), headers);
}

function cleanSpan(id){
document.getElementById(id).innerHTML = '';
}
function odeslat(form) {
                      clearTimeout(clean); 
                      document.getElementById('stav').innerHTML = 'Odesílá se.';
                      form.submit.disabled=true;
    return post_xmlhttprequest(function (xmlhttp) {
    form.text.value = form.text.defaultValue;
        if (xmlhttp.readyState == 4) {
                                        document.getElementById('stav').innerHTML = 'Odesláno'; 
                                        form.submit.disabled=false;
                                        document.getElementById('txt').focus();
                                        clean = setTimeout("cleanSpan('stav');",2000);
                                     
                                     }
    }, './data.php?akce=form&r=<?php print $_GET["rid"]; ?>', form);
}

hlavička
<script>
status = '0';
funkce1(){...}
funkce2(){...}
</script>
tělo

<form action="" method="post" onsubmit="return !odeslat(this);">
<label for="txt"><?php print $_SESSION[nick']; ?>:&nbsp;</label><input type="text" name="text" id="txt" autocomplete="off" maxlength="400" onkeydown="Complete(event,this);">
<input type="checkbox" name="wisp" id="check">
<select name="to" id="to"><option value="0">vyčkejte prosím</select>
<input type="submit" name="submit" value="Odešli">
<span id="stav"></span>
</form>
 patička

function fetchForm(id, callback) {
var oScript = document.getElementById(id);
if (oScript && oScript.readyState && oScript.readyState != 'loaded') { return }
var head = document.getElementsByTagName("head")[0];
if (oScript) { head.removeChild(oScript); }
oScript = document.createElement("script");
head.appendChild(oScript);
oScript.innerHTML = callback;
oScript.id  = id;
oScript.type = 'text/javascript';
}

function fetchForm(id, callback) {
var CScript = document.getElementById(id);
if (CScript && CScript.readyState && CScript.readyState != 'loaded') { return }
var head = document.getElementsByTagName("body")[0];
if (CScript) { head.removeChild(CScript); }
var CScript = document.createElement("script");
var callback = callback;
var ss = document.createTextNode(callback);
CScript.appendChild(ss);
CScript.id  = id;
CScript.type = 'text/javascript';
head.appendChild(CScript);
}

upravovaná část:
    xmlhttp.open(method, url);
    xmlhttp.onreadystatechange = function () {
        state_change(xmlhttp);
    };


upravená část:

    xmlhttp.open(method, url);
    xmlhttp.onreadystatechange = function () {
        if(xmlhttp.readyState == 4 && xmlhttp.status == 200){
        fetchForm('scriptFORM',xmlhttp.responseText);
        }
        state_change(xmlhttp);
    };

function fetchForm(id, callback) {
var CScript = document.getElementById(id);
if (CScript && CScript.readyState && CScript.readyState != 'complete') { return }
var head = document.getElementsByTagName("head")[0];
if (CScript) { head.removeChild(CScript); }
var CScript = document.createElement('script');
CScript.text = callback;
head.appendChild(CScript);
CScript.id  = id;
CScript.type = 'text/javascript';
}