v1$ = "1, 3, -5"
v2$ = "4, -2, -1"

print "DotProduct of ";v1$;" and "; v2$;" is ";dotProduct(v1$,v2$)
end

function dotProduct(a$, b$)
    while word$(a$,i + 1,",") <> ""
       i = i + 1
       v1$=word$(a$,i,",")
       v2$=word$(b$,i,",")
       dotProduct = dotProduct + val(v1$) * val(v2$)
    wend
end function