Configure field actions - Zoho quick start guide error

Hi All,

I'm new to Zoho and am following the quick start guide to build some sample apps and forms. I'm having trouble with an exercise in the Configure Field actions part (https://www.zoho.com/creator/help/getting-started/quick-start-guide.html#field_actions):

While I'm trying to use the fetch deluge task to assign rec variable the value of the record to be fetched from the Product form, I use the expression:

rec = Product[Product_Name == Input.Product];

Following all the instructions in the page, the script is failing with an error that says that I'm trying to assign a string variable a big int value. This is strange as Input.Product is a lookup field type (string) while Product_Name is a single line field (also a string). For someone who has done this exercise, can you please help me out???