浏览器冻结了几秒钟

当下列代码运行时，它会使浏览器冻结几秒钟。我怎样才能避免呢?由于

function rsfp_changePage(formId, page, totalPages, validate)
{
if (validate)
{
    var form = rsfp_getForm(formId);
    if (!ajaxValidation(form, page))
        return false;
}
for (var i=0; i<=totalPages; i++)
{
    var thePage = document.getElementById('rsform_' + formId + '_page_' + i);
    if (thePage)
        document.getElementById('rsform_' + formId + '_page_' + i).style.display = 'none';
}
var thePage = document.getElementById('rsform_' + formId + '_page_' + page);
if (thePage)
{
    thePage.style.display = '';
    try {
        eval('if (typeof rsfp_showProgress_' + formId + ' == "function") rsfp_showProgress_' + formId + '(' + page + ')');
    }
    catch (err) { }
}
}

…

您可以在http://www.ocsl.ch/dev上找到该表单用户名:stackoverflow/密码:stackoverflow先登录，然后转到http://www.ocsl.ch/dev/sejour-linguistique/adultes/demande-d-offre-en-ligne一旦进入这个页面，点击绿色按钮"休眠"，你会看到它冻结了很短的时间。下面的内容是包含ajaxvalidation函数的script.js文件。希望这对你有所帮助。如果你还需要什么帮助，请问我。

function refreshCaptcha(componentId, captchaPath)
{
if(!captchaPath) captchaPath = 'index.php?option=com_rsform&task=captcha&componentId=' + componentId;
document.getElementById('captcha' + componentId).src = captchaPath + '&' + Math.random();
document.getElementById('captchaTxt' + componentId).value='';
document.getElementById('captchaTxt' + componentId).focus();
}
function number_format(number, decimals, dec_point, thousands_sep)
{
var n = number, prec = decimals;
n = !isFinite(+n) ? 0 : +n;
prec = !isFinite(+prec) ? 0 : Math.abs(prec);
var sep = (typeof thousands_sep == "undefined") ? ',' : thousands_sep;
var dec = (typeof dec_point == "undefined") ? '.' : dec_point;
var s = (prec > 0) ? n.toFixed(prec) : Math.round(n).toFixed(prec); //fix for IE parseFloat(0.55).toFixed(0) = 0;
var abs = Math.abs(n).toFixed(prec);
var _, i;
if (abs >= 1000) {
    _ = abs.split(/'D/);
    i = _[0].length % 3 || 3;
    _[0] = s.slice(0,i + (n < 0)) +
          _[0].slice(i).replace(/('d{3})/g, sep+'$1');
    s = _.join(dec);
} else {
    s = s.replace('.', dec);
}
return s;
}
function buildXmlHttp()
{
var xmlHttp;
try
{
    xmlHttp=new XMLHttpRequest();
}
catch (e)
{
    try
    {
        xmlHttp=new ActiveXObject("Msxml2.XMLHTTP");
    }
    catch (e)
    {
        try
        {
            xmlHttp=new ActiveXObject("Microsoft.XMLHTTP");
        }
        catch (e)
        {
            alert("Your browser does not support AJAX!");
            return false;
        }
    }
}
return xmlHttp;
}
function ajaxValidation(form, page)
{
try
{
    var el = form.elements.length;
}
catch (err)
{
    form = this;
}
var xmlHttp = buildXmlHttp();
var url = 'index.php?option=com_rsform&task=ajaxValidate';
if (page)
    url += '&page=' + page;
var params = new Array();
var submits = new Array();
var success = false;
var formId = 0;
for (i=0; i<form.elements.length; i++)
{
    // don't send an empty value
    if (!form.elements[i].name) continue;
    if (form.elements[i].name.length == 0) continue;
    // check if the checkbox is checked
    if (form.elements[i].type == 'checkbox' && form.elements[i].checked == false) continue;
    // check if the radio is selected
    if (form.elements[i].type == 'radio' && form.elements[i].checked == false) continue;
    if (form.elements[i].type == 'submit')
    {
        submits.push(form.elements[i]);
        form.elements[i].disabled = true;
    }
    // check if form is a dropdown with multiple selections
    if (form.elements[i].type == 'select-multiple')
    {
        for (var j=0; j<form.elements[i].options.length; j++)
            if (form.elements[i].options[j].selected)
                params.push(form.elements[i].name + '=' + encodeURIComponent(form.elements[i].options[j].value));
        continue;
    }
    if (form.elements[i].name == 'form[formId]')
        formId = form.elements[i].value;
    params.push(form.elements[i].name + '=' + encodeURIComponent(form.elements[i].value));
}
params = params.join('&');
xmlHttp.open("POST", url, false);
//Send the proper header information along with the request
xmlHttp.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
xmlHttp.setRequestHeader("Content-length", params.length);
xmlHttp.setRequestHeader("Connection", "close");
xmlHttp.send(params);
var success = true;
if (xmlHttp.responseText.indexOf("'n") != -1)
{
    var response = xmlHttp.responseText.split("'n");
    // All spans set to no error
    var ids = response[0].split(',');
    for (var i=0; i<ids.length; i++)
        if (!isNaN(parseInt(ids[i])) && document.getElementById('component'+ids[i]))
            document.getElementById('component'+ids[i]).className = 'formNoError';
    // Show errors
    var ids = response[1].split(',');
    for (var i=0; i<ids.length; i++)
        if (!isNaN(parseInt(ids[i])) && document.getElementById('component'+ids[i]))
        {
            document.getElementById('component'+ids[i]).className = 'formError';
            success = false;
        }
    if (response.length == 4)
    {
        page = parseInt(response[2]) - 1;
        totalPages = parseInt(response[3]);
        rsfp_changePage(formId, page, totalPages, false);
    }
    for (var i=0; i<submits.length; i++)
        submits[i].disabled = false;
}
if (success == false && document.getElementById('rsform_error_' + formId))
{
    try {
        document.getElementById('rsform_error_' + formId).style.display = '';
    }
    catch (err) { }
}
return success;
}
function rsfp_addEvent(obj, evType, fn){ 
 if (obj.addEventListener){ 
   obj.addEventListener(evType, fn, false); 
   return true; 
 } else if (obj.attachEvent){ 
   var r = obj.attachEvent("on"+evType, fn); 
   return r; 
 } else { 
   return false; 
 } 
}
function rsfp_getForm(formId)
{
var formIds = document.getElementsByName('form[formId]');
for (var i=0; i<formIds.length; i++)
{
    if (parseInt(formIds[i].value) != parseInt(formId))
        continue;
    var form = formIds[i].parentNode;       
    if (form.tagName == 'FORM' || form.nodeName == 'FORM')
        return form;
    while (form.parentNode)
    {
        form = form.parentNode;
        if (form.tagName == 'FORM' || form.nodeName == 'FORM')
            return form;
    }
}
}

谢谢@JuanMendes，不幸的是它没有帮助。我做了一些研究，想知道如何修改代码来发送异步请求，但我没有成功。在ajaxValidation函数中，有

xmlHttp.open("POST", url, false);

xmlHttp.open("POST", url, true);

它应该是一个异步请求，不是吗?

当我测试它时，它没有冻结浏览器，但是它不显示错误，如果字段没有填写在表单上。相反，它验证了不应该存在的东西。有什么帮助吗?