ajax

<script type="text/javascript">function send(){var xhr = getXmlHttpRequest();var value = document.getElementById("username").value;//document.write(value);xhr.open("get","send.do?username="+ encodeURI(value),true);//document.write(value);xhr.onreadystatechange = function(){if(xhr.readyState==4){if(xhr.status==200){var text = xhr.responseText;//document.write(text);var info = document.getElementById("info");info.innerHTML=text;}else{info.innerHTML="SYSTEM ERROR";}}};xhr.send(null);}function getXmlHttpRequest(){var xmlHttpRequest = null;if((typeof XmlHttpRequest)!='undefined'){xmlHttpRequest = new XMLHttpRequest();}else{xmlHttpRequest = new ActiveXObject('Microsoft.XMLHttp');}return xmlHttpRequest;}</script>