-----------------------------------form.html---------------------------------------
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">

<head>

<meta http-equiv="Content-Type" content="text/html;charset=UTF-8">

<title>Document</title>

<script type="text/javascript">

function send(){

 var pic = document.getElementsByTagName('input')[0].files[0];

 var fd = new FormData();

 fd.append('pic',pic);


 var xmlhttp = new XMLHttpRequest();


 xmlhttp.onreadystatechange = function(){

 if( this.readyState == 4 && this.status == 200 ){

 document.getElementById('info').innerHTML = this.responseText;

 }

 }



 xmlhttp.open('POST','upload.php',true);

xmlhttp.send(fd);

}

</script>

</head>

<body>

<div id="info"></div>

<form action="">

<input type="file" onchange="send()" />


</form>

</body>

</html>


--------------------------------------upload.php-------------------------------------

<?php 


if(move_uploaded_file($_FILES['pic']['tmp_name'],'./upload/'.$_FILES['pic']['name'] )){

echo '上传成功 ';

}else{

echo '上传失败';

}


 ?>