how to validate for money in jquery

With jQuery validation plugin you can set your own rule using Jack's regular expression (which I haven't tested though) like this:

jQuery.validator.addMethod(
    "money",
    function(value, element) {
        var isValidMoney = /^\d{0,4}(\.\d{0,2})?$/.test(value);
        return this.optional(element) || isValidMoney;
    },
    "Insert "
);

Then you can set the rule within using the validate method:

$("#myForm").validate({
rules: {
    nameOfMyInputField: {
        money: true,
    }
}
});

You can do this with a regular expression: /^\d{0,4}(\.\d{0,2})?$/

EDIT:

Here's the requested fiddle