create a calculation

I have set up calculations for postage on my site (eg 1-5 items £5 - 6-10 items £10 etc) However inside those calculations could be an item that requires special postage. For instance, I sell posters. Most can be sent in tubes and that is what the calculation works out at the moment. However, I also have posters that have to be sent flat and those incur an added expense to the postage. A customer has just ordered 5 posters that can be sent by tube and 1 that has to be sent flat. How can I have a calculation that, if a flat poster is purchased, then the whole postage is then recalcuated rather than the one that is set up at the moment for the tubes? I hoe hat is clear - if not then please let me know.

Also, when I opened eCart today I got the attached error message - don't know what it means

That error just means the Server Behaviors panel hasn't been opened. It happens with the latest version of Dreamweaver. Just open the Server Behaviors window before editing the cart and that shouldn't happen.

In terms of the two shipping charges you could probably add a column to the cart for "ShipFlat" and then set it to 0 or 1 based on the shipping. Then you can have to shipping calculations based on that value to calculate the correct total.

I can't find Server Behaviors panel and I have gone into my Adobe account and downloaded the Add-on. The Creative Cloud says it has been downloaded and added but there is nothing showing up when I open Dreamweaver. Am using Dreamweaver cc2017

Also, I am trying to add some items to my site but te Add to Cart button doesn't seem to be working any longer. Have had a look through the forums but the solutions there don't seem to have any effect

DMXZone has a copy of the Deprecated Server Behaviors panel that you can install with their installer. I've seen issues with installing from the Adobe store not working in some cases so you might try that.

Once installed you will see a menu item Window->Server Behaviors that you can go to to show them on the page.

Add to cart won't work without Server Behaviors installed, so start with that.

Have now got the Server Behavior installed (thank you). Now when I place the cursor on the page where I want the Add to Cart and try to add it nothing happens

Thank you - have reinstalled and it is all working now.

Could I just ask about the other problem I had - about the ShipFlat business:
I have added a column to the cart called ShipFlat and if the poster is a flat one I set the number to 1 otherwise it stays at 0
So, now I have to set up a shipping condition to click in if the ShipFlat is 1
Could you tell me what that condition should be - there are so many and I am getting a bit confused as to which one I should pick. At the moment I have the following added:

AND Number of items with a specific column value If the total number of items where ShipFlat has a value of 1 is = a value of >=1 (does that sound right?) also - do I need to put that condition in the shipping for those without the Flat rate, making the values 0?

I'd need to understand how the shipping should be calculated in order to comment on the specifics of how to set up the charge.

What would the charge be if you order 5 regular and 2 flat posters? How exactly is that calculated?

I think the easiest way to put it is this:

I have the site set up so that (for UK postage):
1) If you purchase 1-5 posters that can be rolled, then the charge is say £5
2) If you were to purchase 4 posters that could be rolled and 1 that was flat then the postage above would be increased to £9
3) If you purchase 6 or more posters that can be rolled then the charge is £8
4) If you purchased 6 posters that could be rolled and 2 that were flat then the postage above would be increased to £12

However, if you only purchased 1 poster that was flat and no other poster then the postage would be the same as example 2. There are only the 4 basic rates for UK and another 4 using the same ratios for International.

Basically, it is due to the postage rates and sizes of the posters that cause the change in the rate that has to be offered when a flat poster is purchased in any order. The mere presence of a flat poster in the order should change examples 1 and 3 into 2 and 4

For instance, someone just ordered 6 posters to be sent to America - 1 of which was flat. The flat rate to send the rolled posters is £8 but when I took the parcel to the post office with the posters wrapped flat the postage went up to £30! So I need to make sure that in future if a flat poster is added to the order then a higher postage rate takes over.

I hope I have explained that clearly. If not then just let me know

I think that you are saying that if 1 or more posters must be flat, then you send all of them flat. So you end up having "rolled" rates and "flat" rates in an all or nothing condition where if 1 is flat they are all mailed flat. Is that correct?

OR do you still roll as many as you can and then have a separate charge for the ones that are flat? How many flat can be bundled in a single shipment? I still don't quite get it.

Yes to first option - all are sent flat if 1 or more are flat. There can be any amount of flat posters - the amount doesn't matter. It is only the fact that there are flat posters being sent in a mixed order. As soon as a flat poster gets added to the order I need the postage to jump to the higher rate