X-Cart forums - Category Template Editing (buy 2 get 1 free)

:(

Right a few months ago some designers created a "buy 2 items receive a 3rd free" now this works lovely. but obviously they didnt give us any clue as to how they done it. later ill show a link of what my category modify looks like. anyway now i want to add special offers such as "buy any 3 vhs titles and receive a free magazine for only бё20"
here is the code that was used to implement the other special offer of buy 2 items get a third free.

Code:

{if $root=="Y"}

<TR>                                                                                                                                                          

 <TD height=10 class=FormButton nowrap>Buy 2 items and get a third one free</TD>                     

 <td width=10 height=10><font class=CustomerMessage></font></td>                                                              

 <TD height=10>                                                                                                                        

  <INPUT type=checkbox name=free value="Y" {if $current_category.free eq "Y"}checked{/if}> (for all subcategories too)                

 </TD>                                                                                                                                                        

</TR>     

{/if}

So now does anyone make any sense of that, it was copied from the admin/main/category_modify.tpl file.

Heres a picture of how the category modify page. http://www.doubled.co.uk/category_modify.JPG

ANYONE GIVE ME SOME HELP I NEED THIS SORTED ASAP I HAVE CHRISTMAS SPECIALS AVAILABLE AND NO WAY OF CODING THEM INTO MY CART SYSTEM. :( :( :(