ASP.NET

void MyGrid_ItemCommand(object o, DataGridCommandEventArgs e)
{
  if (e.CommandName == "Details")
  {
    // do something when "Details" is clicked...
    // perhaps check e.CommandArgument to get to additional
    // data assigned to the button...
  }
}

try

   try
     ' something error-prone
   catch MySpecificException ex
     ' do something
   catch MyCriticalException ex
     throw 

   try
     ' something else error-prone
   catch MySpecificException ex
     ' do something
   catch MyCriticalException ex
     throw 

catch MyCriticalException ex
    ' handle critical exception

SqlConnection connection = new SqlConnection( "ConnectionString" );
SqlCommand cmd = new SqlCommand( "CommandText", connection );
try {
    connection.Open();
    cmd.ExecuteNoneQuery();
}
catch {
    // do something
}

try {
    
    try {
        connection.Open();
    } catch {
        // do something
    }

    try {
         cmd.ExecuteNoneQuery();
    } catch {
        // do something
    }

}
catch {
    // do something
}