jQuery set radio button

I am trying to set a radio button. I want set it by using the value or the id.

This is what I've tried.

$('input:radio[name=cols]'+" #"+newcol).attr('checked',true);

newcol is the id of the radio button.

Maybe a little edit is in order.

There are two sets of radio boxes one with cols and the other with rows. So I see the point in not using id's. My bad. So I have as an example:

<input type="radio" name="rows" class="listOfCols" 
   style="width: 50%; " value="Site"></input>

and

<input type="radio" name="cols" class="listOfCols" 
   style="width: 50%; "  value="Site"></input>

with the id's removed, and I need to set the correct one.