Bouton radio et javascript

Merci Zazzah! Mais ça ne marche pas: le bouton checked ne change pas. Voici mon code:


<FORM name="form_fruit">
<INPUT type="radio" name="fruit" value="Fraise"> Fraise <BR>
<INPUT type="radio" name="fruit" value="Banane"> Banane <BR>
<input type="button" value="Valider" onclick="changebox();">
</FORM>

<SCRIPT language=javascript>


document.getElementsByName("fruit")[0].checked = true;
function changebox(){
document.getElementByName("fruit")[1].cheched = true;
document.getElementByName("fruit")[0].cheched = false;
}

</script>