def preview(self, obj):
    if obj.slide_image:
        try:
            return ("<img src='%s' alt='%s preview'/>" % (obj.slide_image.thumbnail.url, obj.slide_image.title))
        except:
            return ''
    return ''
def preview(self, obj):
    if obj.slide_image:
        try:
            return ("<img src='%s' alt='%s preview'/>" % (obj.slide_image.thumbnail.url, obj.slide_image.title))
        except:
            return 
    return 