SSRS check for NULL or Empty String

Alright..I have a column called "Comments" and need to hide that column if it's NULL or empty or have spaces!

Solution:

Just set the visibility expression to:

=IIF(Fields!Comments.Value = "", IIF(Fields!Comments.Value is nothing, IIF(Len(Trim(Fields!Comments.Value)) = 0,True, False), False), False)