I have a JS object that look something like this.

```
function Product() {
    this.prop1 = 1;
    this.prop2 = 2;
}

function Work(values) {
    this.prodID = 0;
    this.anotherProp = 1;

    this.updateProductID = function(newProdID) {
        var sourceURL = "the URL here";
        alert("ID is: " + this.product.prodID); //displays 0
        $.getJSON(sourceURL, function(data) {

            //I want to update the property like this
            this.product.prodID = data.Products.ProductID;
        })
    };

```

What I am trying to do is make a json call and populate the product.ProdID property of the instance of the Work Object but I always get this.product is undefined.