Help with a FTL if

[Sam Hamilton]

Hi, 

Can someone help me with this if statement - i can only get it to return a 
value for long_description if one exists where as I want it to return a 
description if no long_description is found? 

            <#assign prodDesc = 
productContentWrapper.get("LONG_DESCRIPTION")?if_exists>
            <#if prodDesc?exists>
                ${productContentWrapper.get("LONG_DESCRIPTION")}
            <#else>
                ${productContentWrapper.get("DESCRIPTION")?if_exists}
            </#if>


Thanks
Sam