function getSubitemQuantity(itemindex) {

var min = 0;
var max = 0;
var middle = 0;
max = subs.length - 1;
while (min <= max) {
middle = parseInt((max + min) / 2);
if (itemindex == subs[middle][0]) {
break;
} else if (itemindex < subs[middle][0]) {
max = middle - 1;
} else {
min = middle + 1;
}
}
return subs[middle][1];

}