如何填写输入，如果如此接近字段集，如何检查输入是否已填写。
问题描述：
Really new to JavaScript and html. I would like to be able to create a function that checks if the input field is filled out and if so it closes down the field set. I have written the closing field-set part I just cant figure out how to validate whether the user has filled out the input fields.
<fieldset>
<legend><a href="#" onclick="doit()">Tell us who you are</a></legend>
<div id="one">
<div>
<label> An injured worker</label>
<input type="radio" name="group1" value="injure"/>
</div>
<div>
<label> An employer </label>
<input type="radio" name="group1" value="employee"/>
</div>
<div>
<label> An injured worker and employer </label>
<input type="radio" name="group1" value="both"/>
</div>
</div>
</fieldset>
我的尝试：
函数doit（）{
if（document.getElementById（'one'）。style.display =='none'）{
document.getElementById（'one'）。style.display ='block';
} else {
document.getElementById（'one'） .style.display ='none';
}
}
What I have tried:
function doit() {
if(document.getElementById('one').style.display == 'none'){
document.getElementById('one').style.display = 'block';
} else {
document.getElementById('one').style.display = 'none';
}
}
答
function check（）{
var r = document.getElementsByName（group1）
var c = -1
for（var I = 0;我< r.length; i ++）{
if（r [i] .checked）{
c = i;
}
}
if（c == -1）alert（请选择收音机）;
}
function check() {
var r = document.getElementsByName("group1")
var c = -1
for(var i=0; i < r.length; i++){
if(r[i].checked) {
c = i;
}
}
if (c == -1) alert("please select radio");
}