Thanks for the prompt reply as usual - done that and there is no mention of ItemID in the bindings in Add To Cart function.
Now i get
Microsoft VBScript runtime error '800a000d'
Type mismatch: 'cDbl'
/WA_eCart/ysl_VB.asp, line 15
line 15 is
retVal.ID = cDbl(itemID)
By removing this line, the cart appears (at first test) to work fine - should that be ok to remove that line?