During our discussion on VLOOKUP, we had some questions on how we could show "Not Found".

It turns out either ISERROR or IFERROR will work, with the latter being a bit simpler.

Let us first look at IFERROR with a simple example.

IFERROR(2/0, "Not feasible")

This will return a text string "Not feasible", because you cannot divide any number with zero.  Excel will complain with a #DIV/0! error.

ISERROR, on the other hand, has only one argument, and it just returns a TRUE or FALSE. For example,

ISERROR(2/0) will return a TRUE

So, to prevent an error in VLOOKUP, you can use

=IF(ISERROR(VLOOKUP(...)),"Not Found",VLOOKUP(...))

Or, just simply,

=IFERROR(VLOOKUP(...),"Not Found")

Another great question that I received is how to dynamically reference a cell in a PivotTable, so that you do not lose that value even when the PivotTable has changed its layout. The article below provides a very good answer.

Someone asked: "Is there any guideline in helping me decide which types of graphs to draw for a particular situation?"  What a great question.

Let me share with you a picture: (source: http://extremepresentation.typepad.com/blog/2006/09/choosing_a_good.html)

I like it because it covers most types of charts used in business communications.

Download the above chart chooser as a PDF.