Try - Catch - Finally

You can create (or throw) an exception by using the keyword Throw

Throw New System.Exception 

General Catch Statement

try 
{ 

} 
catch (System.DivideByZeroException ex) 
{ 
   System.Windows.Forms.MessageBox.Show(ex.Message - ex.InnerMessage); 
} 
finally 
{ 
} 

Dedicated Catch Statements

try 
{} 
catch (System.DivideByZeroException ex) 
{} 
catch (System.ArithmeticException ex) 
{} 
catch 
{} 
finally 
{} 

Finally

Any code in the Finally block is guaranteed to be executed regardless of whether an exception is thrown
A finally block can be created with or without catch blocks

Creating your own exceptions

They must derive (directly or indirectly) from the System.ApplicationException

public class MyCustomException 
   : System.ApplicationException 
{ 

   public void New(string message) 
   { 
      MyBase.New(message) 
   } 
} 

InnerException Property

You may want your catch block to take some corrective action first and then rethrow the exception to the outer try block
You may want to refer to the exception history and InnerException property of an exception retrieves the original/previous exception.