Javascript onchange doesn't triggered

Question

On change option, input's value will be changed, but...

<input type="radio" name="1_layer" id="1_1" value="">
<select name="1_select" id="1_1" onchange="schange(this.id)">

I have no idea why is work just first line:

function schange(id) {
    document.getElementById(id).checked=true;
    var sel = document.getElementByName("1_select");
    var val = sel.options[sel.selectedIndex].value; 
    document.getElementByName("1_layer").value == val;
}

Answer 1

There is no method document.getElementByName, but document.getElementsByName. And you should use = instead of ==. So the code is:

function schange(id) {
    document.getElementById(id).checked=true;
    var sel = document.getElementsByName("1_select")[0];
    var val = sel.options[sel.selectedIndex].value;
    document.getElementsByName("1_layer")[0].value = val;
}