Something

<script type="text/javascript">
// JavaScript Document

//Add alert message when error occur
window.onerror = function(msg, err_url, line) {alert('Unknown Error :) ' + line);}

//Detects browser type
function makeObject(){
var x;
var browser = navigator.appName;
if(browser == "Microsoft Internet Explorer"){
x = new ActiveXObject("Microsoft.XMLHTTP");
}else{
x = new XMLHttpRequest();
}
return x;
}

function getData(){
  var theForm = document.getElementById('sample_form');
  var elem = theForm.elements;
  var data = "";
  for(var i=0;i<elem.length;i++){
    var elm = elem[i];
    var nam = elm.name;
    if(elm.length){
      for(var m=0;m<elm.length;m++){
        if(elm[m].selected){
          data += "&"+nam+"="+escape(elm[m].value);
        }
      }
    } else {
      if(!((elm.type=="radio"||elm.type=="checkbox")&&elm.checked==false)){
        data += "&"+nam+"="+escape(elm.value);
      }
    }
  }
  return data;
}

//Call function
var request = makeObject();

//The get method AJAX
function get_method(){

var resultspage = document.getElementById('resultspage').value;

var data = getData();

request.open('get', resultspage+'?data='+data);
request.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
request.onreadystatechange = output;
request.send('');
}

//The POST method AJAX
function post_method(){

var resultspage = document.getElementById('resultspage').value;

var formdata = getData();

request.open('post', resultspage);
request.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
request.onreadystatechange = output;
request.send('data='+formdata);
}

function output()
{
if(request.readyState == 1){
//You can add animated gif while loading //
document.getElementById('output').innerHTML = '<img src="images/loading.gif" /> Searching Domain Names ....';
}
if(request.readyState == 4){
var data = request.responseText;
document.getElementById('output').innerHTML = data;
}
}

//The difference between POST and GET, POST method support or can transffer large data...

</script>
    <div id="main">

<form action="" method="post" name="sample_form" id="sample_form">
	<input type="hidden" value="advdompage.php" name="resultspage" id="resultspage" />
<div class="domainheader">
	<div class="domainform">
	        Domain name:
		<input type="text" name="chk_sld" value="<?=$chk_sld?>" /><br /><br />
		<input type="hidden" name="chk_all" value="1" />
	<input type="button" name="Button" value="POST" onClick="post_method()" />
	</div>
	<div class="domainboxes">
	<?php
	  foreach ($tld_list as $tldval) {
	      echo "<input type=\"checkbox\" name=\"$tldval\" value=\"$tldval\" />.$tldval";
	  }
	?>
	</div>
	<div style="clear:both;"></div>
</div>
</form>

<div style="margin-top:20px;" id="output"></div>
	</div>