[DBK Web Builder]

I got this to work by doing the math in the assign

{assign var='iprev' value='100'}

{foreach from=$pages_menu item=p name=page}
{if $p.orderby gte 100 }
{assign var='idiff' value=$p.orderby - $iprev}

....
{assign var='iprev' value='200'}

etc.

thanks for pointing me in the right direction !

Donna