Making a program to find the square root of any number

[MartinLiss]

Here's the first part.

Function CalculateSquareRoot(NumberArg As Double) As Double
   If NumberArg < 0 Then   ' Evaluate argument.
      Exit Function   ' Exit to calling procedure.   
   Else
      CalculateSquareRoot = Sqr(NumberArg)   ' Return square root.   
   End If
End Function