如何检查是否使用JavaScript检查了单选按钮？

Question

When I select a radio button then click the download button, nothing happens. No alert shows up or anything.

Here is my code right now:

HTML:

<form id="Resume_Select">
<input type="radio" name="resume_type" value="Economics" >Economics
<br />
<input type="radio" name="resume_type" value="MIS" >Management Information Systems
<br />
<button onClick="resume_select()"> Download</button>
</form>

JavaScript:

<script>
    function resume_select(){
    var radios = document.getElementByName('resume_type');
    for(var i = 0, length = radios.length; i<length;i++){

        if(radios[i].checked){
            var resume = radios[i].value;
            alert(radios[i].value);
            break;
        }
    }

</script>

Answer 1

It should be getElementsByName plural not getElementByName. First thing that jumped at me.