JavaScript 三种弹窗对话框实现详解

<html>
<head>
<script type="text/javascript">
function disp_alert()
{
alert("我是警告框！！")
}
</script>
</head>
<body>
<input type="button" onclick="disp_alert()" value="显示警告框" />
</body>
</html>

<html>
<head>
<script type="text/javascript">
function disp_confirm()
{
var r=confirm("按下按钮")
if (r==true)
  {
  document.write("您按了确认！")
  }
else
  {
  document.write("您按了取消！")
  }
}
</script>
</head>
<body>
<input type="button" onclick="disp_confirm()" value="显示确认框" />
</body>
</html>

<html>
<head>
<script type="text/javascript">
function disp_prompt()
{
var name=prompt("请输入您的名字","Bill Gates")
if (name!=null && name!="")
  {
  document.write("你好！" + name + " 今天过得怎么样？")
  }
}
</script>
</head>
<body>
<input type="button" onclick="disp_prompt()" value="显示提示框" />
</body>
</html>