javascript驗證radio

[SCRIPT LANGUAGE="JavaScript"]
function validate(){
var count = 0;
for(i=0;i if(activeForm.syscate[i].checked){
count++;
alert(activeForm.syscate[i].value)
}
}
if(count==0){
alert('您必須選擇文章所屬欄目！！！');
return false;
}
}
[/SCRIPT]
[FORM METHOD=POST name="activeForm" onsubmit="return validate()"]
[INPUT TYPE="radio" id="syscate" NAME="a.test" value="1" ]文章欄目一
[INPUT TYPE="radio" id="syscate" NAME="a.test" value="2"] 文章欄目二
[INPUT TYPE="submit"]
[/FORM]