jQuery case à cocher question

Question

comment puis-je faire fonctionner la 5ème case avec "cochée" ou "non cochée"?

var price_1_startup = 800; 
var price_1 = 0; 

function upgrade_1(str) { 
    if (str == 1) {price_1 = 0;} 
    else if (str == 2) {price_1 = +125;} 
    else if (str == 3) {price_1 = +200;} 
    else if (str == 4) {price_1 = +325;} 
    $("#price_1").hide().html(price_1_startup+price_1).fadeIn('slow'); 
} 
function checkbox() { 
    $("#price_1").hide().html(price_1_startup+1500).fadeIn('slow'); 
} 

---

<input type="radio" name="upgrade1" value="1" onclick="upgrade_1(this.value);" checked="checked" /><br> 
<input type="radio" name="upgrade1" value="2" onclick="upgrade_1(this.value);" /><br> 
<input type="radio" name="upgrade1" value="3" onclick="upgrade_1(this.value);" /><br> 
<input type="radio" name="upgrade1" value="4" onclick="upgrade_1(this.value);" /><br> 
<input type="checkbox" name="upgrade1" value="5" onclick="checkbox(this.value);" /><br> 

Answer 1

jQuery('input[value="5"]').attr('checked', true); 

Cela vous obtenir la valeur de bouton vérifier actuellement radio (1, 2, 3, 4)

var selected = parseInt(jQuery('input[type="radio"][name="upgrade1"]:checked').val());