EDIT: OOPS -- saw you were in 4.2 -- some of this advice will not be applicable, but the ideas are the same
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Alison,
The template, /skin1/customer/main/welcome.tpl contains a language variable, {$lng.txt_welcome} -- You have a few choices:
1. put your html into the $lng.txt_welcome language var
2. REPLACE {$lng.txt_welcome} with your html code
3. Make a new template file and call it homepage.tpl - then call it from welcome.tpl instead of {$lng.txt_welcome} -- like this:
Code:
{* {$lng.txt_welcome} *}
{include file="customer/main/homepage.tpl"}
4. Forget about welcome/tpl altogether, and just make a new homepage.tpl, and call it from /skin1/customer/home_main.tpl -- instead of welcome.tpl
Code:
{elseif $main eq "catalog" and $current_category.category eq ""}
{include file="customer/main/homepage.tpl"}
{* {include file="customer/main/welcome.tpl" f_products=$f_products} *}
(however doing this my way will kill off the featured products. but you can make your own version of featured products.)
Good luck!
Jeremy