error '80020009'

I am getting error '80020009'


while doing this


the error is on the line response.write productid

sub showalsolike(productid)
response.write productid
''here i open the db and pull the product out
end sub

nevermind i figured this out - it must have been calling with a blank productid though i still don't know why that didn't just display a blank productid rather then erroring