Paypal integration issue in titanium

Why are you escaping the quotes in this code?

[{"name":"Bajaj 200 mm Ultima PT01 Personal Fan","totalPrice":2997,"itemPrice":999,"itemCount":3}

This is not valid JSON (or Javascript for that matter). Is this required by Paypal? I think it should look like this:

[{"name":"Bajaj 200 mm Ultima PT01 Personal Fan","totalPrice":2997,"itemPrice":999,"itemCount":3}

Edit:

I've had a closer look at your code sample. Can you confirm where totatamount is coming from? As the code sample stands it will be undefined, which would be consistent with the error message you have described. Can you confirm it is definitely the correct value IMMEDIATELY before you submit this data?

The ti.paypal spec has a nice code sample in the README file, which gives a good example of how to setup createPaypalButton. I would recommend looking at this if you haven't already.

button = Paypal.createPaypalButton({    // NOTE: height/width only determine the size of the view that the button is embedded in - the actual button size    // is determined by the buttonStyle property!    width: 194 + u, height: 37 + u,    buttonStyle: Paypal.BUTTON_194x37, // The style & size of the button    bottom: 50 + u,    language: 'en_US',    textStyle: Paypal.PAYPAL_TEXT_DONATE, // Causes the button's text to change from "Pay" to "Donate"    appID: '<<<YOUR APP ID HERE>>>', // The appID issued by Paypal for your application; for testing, feel free to delete this property entirely.    paypalEnvironment: Paypal.PAYPAL_ENV_SANDBOX, // Sandbox, None or Live    feePaidByReceiver: false, // This will only be applied when the transaction type is Personal    enableShipping: false, // Whether or not to select/send shipping information    advancedPayment: { // The payment itself        payments: [            {                isPrimary: true, // Mark this as the primary vendor; this marks this as a chain payment.                merchantName: 'Primary Vendor',                paymentType: Paypal.PAYMENT_TYPE_SERVICE, // The type of payment                paymentSubtype: Paypal.PAYMENT_SUBTYPE_DONATIONS, // The subtype of the payment; you must be authorized for this by Paypal!                subtotal: 13, // The total cost of the order, excluding tax and shipping                tax: 0,                shipping: 0,                recipient: '<<<YOUR RECIPIENT HERE>>>',                customID: 'anythingYouWant',                invoiceItems: [                    { name: 'Shoes', totalPrice: 8, itemPrice: 2, itemCount: 4 },                    { name: 'Hats', totalPrice: 2, itemPrice: 0.5, itemCount: 4 },                    { name: 'Coats', totalPrice: 3, itemPrice: 1, itemCount: 3 }                ]            },            {                merchantName: 'Vendor 1',                paymentType: Paypal.PAYMENT_TYPE_SERVICE, // The type of payment                paymentSubtype: Paypal.PAYMENT_SUBTYPE_DONATIONS, // The subtype of the payment; you must be authorized for this by Paypal!                subtotal: 10, // The total cost of the order, excluding tax and shipping                tax: 0,                shipping: 0,                recipient: '<<<YOUR RECIPIENT HERE>>>',                customID: 'anythingYouWant',                invoiceItems: [                    { name: 'Shoes', totalPrice: 8, itemPrice: 2, itemCount: 4 },                    { name: 'Hats', totalPrice: 2, itemPrice: 0.5, itemCount: 4 }                ]            },            {                merchantName: 'Vendor 2',                paymentType: Paypal.PAYMENT_TYPE_SERVICE, // The type of payment                paymentSubtype: Paypal.PAYMENT_SUBTYPE_DONATIONS, // The subtype of the payment; you must be authorized for this by Paypal!                subtotal: 3, // The total cost of the order, excluding tax and shipping                tax: 0,                shipping: 0,                recipient: '<<<YOUR RECIPIENT HERE>>>',                customID: 'anythingYouWant',                invoiceItems: [                    { name: 'Coats', totalPrice: 3, itemPrice: 1, itemCount: 3 }                ]            }        ],        ipnUrl: 'http://www.appcelerator.com/',        currency: 'USD',        memo: 'For the orphans and widows in the world!'    }});