title: If Error Then Blank
body: <p>Thanks for taking a look at my question. Know that I am new to stackoverflow and VBA I have a long macro I've been working on. At one point in the macro I have to convert "Start Depth" (L) and "End Depth" (M) from "m" to "ft". Then I subtract the two to find the "Footage" (N). However, some of the values in the columns are originally left blank. So, after making my conversions and subtractions, I'm left with "#VALUE!" which is giving me errors later on in the macro. Originally I had changed all of the blanks to 0's before the conversions and subtractions. But, After "finishing" the macro I realize the zeros are messing with presenting the data. So, I'd like to just do the conversions and subtractions and then, change all the "#VALUES!" back to blanks. I found some stuff on this but nothing that I could (that i know of) use or specific to me:
  <a href="http://www.ozgrid.com/forum/showthread.php?t=60740" rel="nofollow noreferrer">http://www.ozgrid.com/forum/showthread.php?t=60740</a>     and    <a href="https://superuser.com/questions/715744/excel-2010-formula-how-do-i-write-this-formula-vba">https://superuser.com/questions/715744/excel-2010-formula-how-do-i-write-this-formula-vba</a></p>
  
  <p>Here is what i was using to change blanks into 0's</p>
  
  <pre><code>Worksheet1.Select
  lastrow = Range("A666666").End(xlUp).Row
  For Each cell In Range("A1:Q" &amp; lastrow)
      If Len(cell.Value) = 0 Then
          cell.Value = 0
      End If
  Next
  </code></pre>
  
  <p>Here is the code resulting in errors. Note: The data starts with blanks and after using these formulas I am given errors because some of the original cells begin as null or blanks. Also, These lines aren't in this order but, they are the lines leaving errors.</p>
  
  <pre><code>ActiveCell.FormulaR1C1 = "=CONVERT(RC[2],""m"",""ft"")"
  Selection.AutoFill Destination:=Range("N2:O2"), Type:=xlFillDefault
  Selection.AutoFill Destination:=Range("N2:O" &amp; lastrow)
  Range("N1") = "Footage"
  Range("N2").Select
  ActiveCell.FormulaR1C1 = "=RC[-1]-RC[-2]"
  Selection.AutoFill Destination:=Range("N2:N" &amp; lastrow)
  </code></pre>
  
  <p>Any help is appreciated. Thanks guys!</p>