Hi Jagan!
Sorry about the delay there!
From what I understand, you just want a way in Javascript to get the value of your cart. As long as you are on your Shopify site, you can use
Shopify.getCart()
his will return a JSON object that has a "total price" field.
If you are not on your Shopify shop, I think you can use JQuery Ajax commands with a jsonp data type (allows cross site requests). Something like this could help (will require some tinkering).
$.ajax({ url: visitorengage.com/cart.js, success: successCallback, dataType: jsonp });
Take a look at these links for more help:
Docs: http://docs.shopify.com/support/your-website/themes/can-i-use-ajax-api
Playground with the API: http://mayert-douglas4935.myshopify.com/pages/api
I hope this helps!
Julian Nadeau
Shopify Mobile