Using jQuery validator plugin, how to use dynamically created name attributes to assign rules?

Here's the problem:

The ecommerce system we uses generates a line item for each product purchased. It gives line item's quantity input the name attribute "qty0", "qty1", "qty2", and so on as the line items go down the page.

I need to check these qtyX inputs for validity, but I don't know how to pass either the name attribute as a relative attribute of another attribute like a class, or pass a regex to the validate plugin to find all the quantity fields.

Here's the validate code:

var validator = $("#formName").validate({
    rules: {
        qty: { customMethod: true}// qty
        },//rules

    messages: {
        qty: {customMethod: "NOPE"}
    },

    errorPlacement: function(error, element) {
            error.appendTo("#itemQuantityError");
    },

});

Here's a sample of the input that gets generated:

<td ><input name="qty1" value="6" size="5"></td>

Thank you!!

You could generate the rules and the messages dynamically:

var rules = new Object();
var messages = new Object();
$('input[name^=qty]:text').each(function() {
    rules[this.name] = { required: true };
    messages[this.name] = { required: 'This field is required' };
});

var validator = $("#formName").validate({
    rules: rules,
    messages: messages,
    errorPlacement: function(error, element) {
        error.appendTo("#itemQuantityError");
    }
});