Question: I am using a simple TABLE to display tabular data where the rows need to line up but when it comes to selecting the table contents, I only want users to be able to select within each column. Default browser behaviour is to select as rows across all columns but we NEED somehow allow selection only within columns.

I was hoping there was a fancy new CSS or XHTML 1.0 way to define tables as columns instead of rows and browsers would then force selection within them. I know realize this probably isn't possible and will need to build a javascript selection way to override browser selection. Obviously javascript spreadsheet widgets like Google Spreadsheets allow selection within rows and columns as I require but I am hoping to find a grid-type widget built on Prototype or write my own functionality.

Any tips or links to widgets with this column selection builtin? Is there an HTML/CSS trick to make something like this work?

Answer: 
I had this problem by including `parent.h` before `iostream`:

wrong:

```
include "parent.h"
include <iostream>

```

right:

```
include <iostream>
include "parent.h"

```
When you say

```
A instance;

```

you will create a new object of type A. But you have already said that A isa an abstract class, so you can't to that. You need to use a pointer, as several otherrs have indicated, or make A non-abstract.