Ajax_showHint() 函数

时间:2024-10-02 14:36:50

showHint() 函数实现的功能是:当用户在输入框中键入字符时,网页如何与 web 服务器进行通信,完整的代码如下:

<html>
<head>
<script type="text/javascript">
function showHint(str)
{
var xmlhttp;
if (str.length==0)
  { 
  document.getElementById("txtHint").innerHTML="";
  return;
  }
if (window.XMLHttpRequest)
  {// code for IE7+, Firefox, Chrome, Opera, Safari
  xmlhttp=new XMLHttpRequest();
  }
else
  {// code for IE6, IE5
  xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
  }
xmlhttp.onreadystatechange=function()
  {
  if (xmlhttp.readyState==4 && xmlhttp.status==200)
    {
    document.getElementById("txtHint").innerHTML=xmlhttp.responseText;
    }
  }
xmlhttp.open("GET","/ajax/gethint.asp?q="+str,true);
xmlhttp.send();
}
</script>
</head>
<body>

<h3>请在下面的输入框中键入字母(A - Z):</h3>
<form action=""> 
姓氏:<input type="text" id="txt1" onkeyup="showHint(this.value)" />
</form>
<p>建议:<span id="txtHint"></span></p>

</body>
</html>