Delete rows that are empty across columns

[ALATL]

I have the following columns that are a result of a pivot table. I would like
to delete the folllowing occurences. I tried using the range function but got
a runtime error 1004. Something like:

' If Not Range("Col1").Value Is Nothing Then
' Rows.Delete

Col1 Col2
a a b
X X X
X (delete)
X X
X X
X (delete)

I want to delete rows where Col1 = X and Col2 = X does not exist. To
complicate things, this is a pivot table where Col1 and Col2 are further
broken down into a and b. I thought that by using Range that a and b would
not need to be accounted for individually. Thanks for any help!