I will prefer to use a class name for the controls(textboxes)... In furtur days if adding new cols also there won't be any problem ....

Example:

<table>

<tr>

<td>

<input type='text' class='col1' />

</td>

</tr>

<tr>

<td>

<input type='text' class='col1' />

</td>

</tr>

</table>

In the above table u have two rows with one cols, each row has a textbox .. with same class name ..

Now the Jquery Code Will Be like ...

var sumofCol1 = 0;

$('.col1').live('keyup', function() {

$('input.col1').each(function(){

sumofCol1 = sumofCol1 + $(this).val();
});

});

Finally Assign sumofCol1  to a label in the footer ....

I used live for evnt binding because, you are creating row at time ... so 'live' ll be help full...

** Take Care of Converting value to int or float e.t.c ...