I'm doing some error debugging trying to get the errors on our website down to a minimum and there seems to be an error that is popping up quite a lot

Conversion from string "" to type 'Double' is not valid.

I'm unable to replicate this problem but I can see that it is happening.

I've been looking through the code in one of the pages and strolled across this

Dim varWeek As String

If varWeek < 10 Then
    'Do something'
End If

Could this be causing the problem as it is trying to see if a String is less than 10 which is an Integer?

As I said before as I am unable to see this error in the first place so changing this to an Integer doesn't change anything on my system.

Thanks.