Customization in Item Details and Sales Order Details form

Hi All,

I have a requirement where I have to create new Warranty Form and from here i need to select in Item details form.

After this when I will create new Sales Order then in sales line, I want this new field to take same warranty which I have

inserted in Item Details form.

Kindly help me in this as I have little knowledge to do form customization.

Thanks in advance.