HTML中的alert的运用，帮帮忙
<%@ page language= "java " pageEncoding= "ISO-8859-1 "%>
<%@ taglib uri= "http://struts.apache.org/tags-bean " prefix= "bean " %>
<%@ taglib uri= "http://struts.apache.org/tags-html " prefix= "html " %>
<%@ taglib uri= "http://struts.apache.org/tags-logic " prefix= "logic " %>
<%@ taglib uri= "http://struts.apache.org/tags-tiles " prefix= "tiles " %>
<html>
<head>
<title> MyJsp.jsp </title>
<script type= "text/javascript ">
function al()
{
alert(radio1.value);
}
</script>
</head>
<body>
<table width= "100% " border= "1 " height= "40% ">
<tr> <td align=center width= "40% " height=400>
<table>
<tr> <td> <strong> 请输入编号 </strong> <br> <input type=text name=number /> </td> </tr>
</table>
</td>
<td> <strong> 点击选择类型 </strong>
<br> <input type= "radio " name= "radio1 " checked=checked value= "A " /> Ａ
<br> <input type= "radio " name= "radio1 " value= "B " /> Ｂ
<br> <input type= "radio " name= "radio1 " value= "C " /> Ｃ
<br>
<br> <input type=button name=cancle value= "取消 "/>
<input type=button name=next value= "上一步 " />
<input type=button name=next value= "进入 "; onclick= "al() " />
</td> </tr>
</table>
</body>
</html>
我按了进入按钮后,就提示undefine,请问一下哪里错了?
[解决办法]
<script>
function b()
{
o = document.getElementsByName( "a ");
for(c=0;c <o.length;c++)
{
if(o[c].checked) alert(o[c].value);
}
}
</script>
<input type= "radio " name= "a " value= "a ">
<input type= "radio " name= "a " value= "b ">
<input type= "radio " name= "a " value= "c ">
<input type= "button " onclick= "b() ">
[解决办法]
<!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 ">
<head>
<meta http-equiv= "Content-Type " content= "text/html; charset=gb2312 " />
<title> 无标题文档 </title>
<script type= "text/javascript ">
function al()
{
var radio1 = document.getElementsByTagName( "input ");
for(var i=0;i <radio1.length;i++)
{
if(radio1[i].getAttribute( "checked ")){
alert(radio1[i].getAttribute( "value "));
}
}
}
</script>
</head>
<body>
<table width= "100% " border= "1 " height= "40% ">
<tr> <td align=center width= "40% " height=400>
<table>
<tr> <td> <strong> 请输入编号 </strong> <br> <input type=text name=number /> </td> </tr>
</table>
</td>
<td> <strong> 点击选择类型 </strong>
<br> <input type= "radio " name= "radio1 " checked= "checked " value= "A " /> Ａ
<br> <input type= "radio " name= "radio1 " value= "B " /> Ｂ
<br> <input type= "radio " name= "radio1 " value= "C " /> Ｃ
<br>
<br> <input type=button name=cancle value= "取消 " />
<input type=button name=next value= "上一步 " />
<input type=button name=next value= "进入 "; onclick= "al() " />
</td> </tr>
</table>
</body>
</html>
[解决办法]
错误的原因：radio1.value中的radio1为数组，要获取选择的radio值，应该这样：
function al()
{
var rd=document.getElementsByName( "radio1 ");//获得所有名为radio1的对象数组
//遍历rd,找到选择的radio
for(i=0;i <rd.length;i++)
{
if(rd[i].getAttribute( "type ")== "radio " && rd[i].checked)
{
alert(rd[i].value);
break;
}
}
}