Короче нашел решение проблемы, правда все таки через цикл. Если кому интересно - код:
<form name="form_fabric_inner">
<input type="checkbox" name="fabric_inner" id="Кожа" value="Кожа"><div onclick = "f_img_fabric_inner('Кожа');"></div>
<input type="checkbox" name="fabric_inner" id="Кожзам" value="Кожзам"><div onclick = "f_img_fabric_inner('Кожзам');"></div>
</form>
function f_img_fabric_inner(d) {
var d
for(i=0; i < document.form_fabric_inner.fabric_inner.length; i++) {
if(document.form_fabric_inner.fabric_inner.item(i) .value == d) {
switch(document.form_fabric_inner.fabric_inner.ite m(i).checked) {
case true:
document.form_fabric_inner.fabric_inner.item(i).ch ecked = '';
break;
case false:
document.form_fabric_inner.fabric_inner.item(i).ch ecked = 'checked';
break;
}
}
}
f();
}