Separator Between grid columns

Question

how can i add separator between grid columns. I try adding border and it always broke the layout. Please have a look at the attached picture for clear understanding.

EDIT

have a look it here

http://burnfatweightlossblog.com/aiu/junaid/testhtml/

code

<div class="container_12">
  <div id="footer">
    <div class="alpha grid_3 dabox"> </div>
    <!-- Box 1-->
    <div class="grid_3 dabox"> </div>
    <!-- Box 2-->
    <div class="grid_3 dabox"> </div>
    <!-- Box 3-->
    <div class="omega grid_3 dabox"> </div>
    <!-- Box 4--> 
  </div>
  <!-- footer--> 
</div>

Answer 1

Adding border would add extra 1px , so it breaks the layout, instead of adding border to grid column, try adding a div inside of it and give border to it ...