I am copying all pages over from yahoo sitebuilder to BV sitebuilder.

I was looking at the BV tuitorial on how to insert iframes and it shows a
step to insert a URL.

On my yahoo sitebuilders Mals cart page, I just had to copy all of the html into the iframe and did not have to name a url in its properties.

So, I am not sure what I will need to do. Add what URL? Is it needed?