Klikke på billede i stedet for radio button

onclick="document.getElementById('myRadio').checked=true"

<style type="text/css">
.fooBar input {
    position: absolute;
    left: -10000px;
    top: -10000px;
}
</style>

<script type="text/javascript">
var actElm = "myCars_2";

function setRadio(elmLabel) {
    actElm = typeof actElm=="string" ? document.getElementById(actElm).parentNode : actElm;
    actElm.getElementsByTagName("img")[0].setAttribute("src", "radio_off.png");
    elmLabel.getElementsByTagName("img")[0].setAttribute("src", "radio_on.png");
    actElm = elmLabel;
}
</script>

<form action="">
<div class="fooBar">
    <label for="myCars_1" onclick="setRadio(this)">Bil #1: <img src="radio_off.png" alt=""><input id="myCars_1" name="myCars" value="1" type="radio"></label>
    <label for="myCars_2" onclick="setRadio(this)">Bil #2: <img src="radio_on.png" alt=""><input id="myCars_2" name="myCars" value="2" type="radio" checked="checked"></label>
    <label for="myCars_3" onclick="setRadio(this)">Bil #3: <img src="radio_off.png" alt=""><input id="myCars_3" name="myCars" value="3" type="radio"></label>
</div>
</form>

<style type="text/css">
.fooBar input {
    position: absolute;
    left: -10000px;
    top: -10000px;
}
</style>

<script type="text/javascript">
var groupActiveElms = {
    "myCars": "myCars_2",
    "myBikes": "myBikes_3"
};

function setRadio(elmLabel) {
    var sGroup = document.getElementById(elmLabel.getAttribute("for")).getAttribute("name");
    var actElm = groupActiveElms[sGroup];
    actElm = typeof actElm=="string" ? document.getElementById(actElm).parentNode : actElm;
    actElm.getElementsByTagName("img")[0].setAttribute("src", "radio_off.png");
    elmLabel.getElementsByTagName("img")[0].setAttribute("src", "radio_on.png");
    groupActiveElms[sGroup] = elmLabel;
}
</script>

<form action="">
<div class="fooBar">
    <label for="myCars_1" onclick="setRadio(this)">Bil #1: <img src="radio_off.png" alt=""><input id="myCars_1" name="myCars" value="1" type="radio"></label>
    <label for="myCars_2" onclick="setRadio(this)">Bil #2: <img src="radio_on.png" alt=""><input id="myCars_2" name="myCars" value="2" type="radio" checked="checked"></label>
    <label for="myCars_3" onclick="setRadio(this)">Bil #3: <img src="radio_off.png" alt=""><input id="myCars_3" name="myCars" value="3" type="radio"></label>
</div>

<div class="fooBar">
    <label for="myBikes_1" onclick="setRadio(this)">Bike #1: <img src="radio_off.png" alt=""><input id="myBikes_1" name="myBikes" value="1" type="radio"></label>
    <label for="myBikes_2" onclick="setRadio(this)">Bike #2: <img src="radio_off.png" alt=""><input id="myBikes_2" name="myBikes" value="2" type="radio"></label>
    <label for="myBikes_3" onclick="setRadio(this)">Bike #3: <img src="radio_on.png" alt=""><input id="myBikes_3" name="myBikes" value="3" type="radio" checked="checked"></label>
</div>
</form>