anchor.diff:  
           .row
             .col-md-1
  -            |Collection <br>
  +            p="Collection"
             .col-md-10
               textarea.form-control(id="collection" name="collection" rows=2) #{article.collection}
           .row
  
positive.code: 
          .row
            .col-md-1
              |Category <br>
            +leftcolumn
              select(id="categoryEN",name="categoryEN").form-control
                for category in categories
  
negative.code:       .row
          if article.categoryEN != "Picture"
            .col-md-1
              p="Preview"
  
  
            +leftcolumn 
  