1. Chat.html 
  2. ---------
  3.  
  4. <html>
  5. <head>
  6. <script type="text/javascript">
  7. function showUser(str)
  8. {
  9. if (str=="")
  10.   {
  11.   document.getElementById("chat").innerHTML="";
  12.   return;
  13.   }
  14. if (window.XMLHttpRequest)
  15.   {// code for IE7+, Firefox, Chrome, Opera, Safari
  16.   xmlhttp=new XMLHttpRequest();
  17.   }
  18. else
  19.   {// code for IE6, IE5
  20.   xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
  21.   }
  22. xmlhttp.onreadystatechange=function()
  23.   {
  24.   if (xmlhttp.readyState==4 && xmlhttp.status==200)
  25.     {
  26.     document.getElementById("chat").innerHTML=xmlhttp.responseText;
  27.     }
  28.   }
  29. xmlhttp.open("GET","chat.php?q="+str,true);
  30. xmlhttp.send();
  31. }
  32. </script>
  33. </head>
  34. <body>
  35.  
  36. <form name="form">
  37. <input type="text" id="text">
  38. <input type='submit' onclick="showUser(document.form.getElementById("text").value)">
  39. </form>
  40.  
  41. <div id="chat">cdffdsfafs</div>
  42.  
  43. </body>
  44. </html>
  45.  
  46. -------
  47. Chat.php
  48. -------
  49. <?php
  50. $response="VLOL";
  51. echo $response;
  52. ?>