Now it gets a bit more complicated. Once we have selected a database, we should decide which elements of the database we need. Selecting an element is done by the following procedure: click on the needed element in one of the lists. The frame on the right then displays which element is selected in the Column identification textfield. Press the Description button for a short description of the element (an example of a column content is given between brackets <example>). Then one must decide if the selected element should be visible or hidden in the final output. One only makes an element hidden if the element is used just for restricting the final output without displaying that element. One may press Reject if the element is not needed. By pressing Accept we make the element the first column of our eventual output. One can click through the already selected columns by using the << and >> buttons. The element which shows up in the Column identification textfield can then be rejected or its Columnstyle (visible or hidden) can be changed in a later stage. If one is satisfied with the selected elements one should click the Ok button to proceed to the restrictions screen.
Please note that one can easily click the wrong field in the pulldown menus; therefore one should check the selected columns by clicking through them (<< and >>) or check the selected columns in the restrictions screen. Furthermore, one should not select a given column twice; no results will be displayed. One can display the same column multiple times in the final output by using user-defined columns (see Restrictions).