how to fill in content area when empty

I added a right module but when there is nothing to display in the content area I would like the background to be filled in with white but I can not figure out how to do that without also added white into other module that I don't want to show white.

see the picture

fwmdev.com/miss2/index.php/used-cars/ite...tegory/38-commercial

open index.php of template, find this code:

below } insert:

if($mpostion[0] == "<position name>") { $modules_in_row++; }

change <position name> with actual position name

The position is "content" if there is already "joom_content" is that the same thing?

adding this:
" if($mpostion[0] == "content") { $modules_in_row++; "

did not do anything

Also I don't understand how to use the equal heights in the back end as I do not see an example of it and the video is too blurry.

There is no position named "content", for content position name is "joom_content". You could do this:

modify :
if($mpostion[0] == "joom_content") { $modules_in_row++; }

to:

if($mpostion[0] == "joom_content") { $modules_in_row++; $mpostion[0] .= " tcontent"; }


then add this script just above </head>

<script type="text/css">
jQuery(document).ready(function(){
if(!jQuery.trim(jQuery('.tcontent').text()))
jQuery('.tcontent').css('background','transparent');

});
</script>