How to add attributes in grouped product

Hello Sir,
Thanks for the reply.
As you can see in this page http://aureusart.com/Ecommerce/product/product/
there are quantity,name and price column with their values,
what I want is I want create one more column named as “Size”,with their respected values in the dropdown.So that user can select which size they want.

Please let me know the solution.

Thanks

Hello Sir,
I dont know how do I make you understand.
I know about variable product,this is used in single product single page.Not in Multiple product in single page.

I am asking about Grouped product.
I have tried to add attribute column “Size” in this page with their values by using this code

<td class=”label”>
<label for=”product-<?php echo $product_id; ?>”>
<?php echo $product->get_attribute( ‘size’ ); ?>
</label>
</td>
http://aureusart.com/Ecommerce/product/product/

Now I want these values in drop down box so that user can select for further process.

Expecting right solution from you.

Thanks

Ok Thanks