<{if $xoBlocks.canvas_left and $xoBlocks.canvas_right}><{assign var=columns_layout value='threecolumns-layout'}>
<{elseif $xoBlocks.canvas_left}><{assign var=columns_layout value='leftcolumn-layout'}>
<{elseif $xoBlocks.canvas_right}><{assign var=columns_layout value='rightcolumn-layout'}>
<{/if}>
class="<{$columns_layout}>"<{/if}>>