function check()
{
if (document.getElementById('c1').checked){
document.getElementById('c2').checked == true;
}
if (document.getElementById('c2').checked){
document.getElementById('c1').checked == true;
}
}<input type="radio" name="aa" id="c1" value="1" >和<input type="radio" id="c2" name="aa" value="2" > <input name="button22" type="button" id="button222" onclick=check(); value="换" >
{
if (document.getElementById('c1').checked){
document.getElementById('c2').checked == true;
}
if (document.getElementById('c2').checked){
document.getElementById('c1').checked == true;
}
}<input type="radio" name="aa" id="c1" value="1" >和<input type="radio" id="c2" name="aa" value="2" > <input name="button22" type="button" id="button222" onclick=check(); value="换" >
"http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<title>无标题文档</title>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
</head>
<script language="JavaScript">
function check()
{
if (document.getElementById('c1').checked){
document.getElementById('c2').checked = true;
return true;
}
if (document.getElementById('c2').checked){
document.getElementById('c1').checked = true;
return true;
}
}
</script>
<body><form><input type="radio" name="aa" id="c1" value="1" ><input type="radio" id="c2" name="aa" value="2" > <input name="button22" type="button" id="button222" onclick="return check()" value="换" >
</form>
</body>
</html>
<input type="radio" name="aa" value="2" ><input type="button" value="select" onclick="if(document.all.aa[0].checked){document.all.aa[1].checked=true;}else{document.all.aa[0].checked=true;}">
document.getElementById('c2').checked == true;
document.getElementById('c1').checked == true;
这两句好像没起到作用?????