/** Sets the A class message to aHtml.
        *   @param aHtml a ready to use html. */
        function setMessage(aHtml) {
            document.getElementById("private").innerHTML=aHtml;
        }
        
        /** Adds a BCD category message to the display.
        *   @param aHtml a ready to use html. */
        function addContent(aHtml) {
            doShift();
            document.getElementById("c0").innerHTML=aHtml;
        }
        
        /**
        *   Shifts the public (sytem) messages by one. */
        function doShift() {
            for (i=20;i>0;i--) {
                document.getElementById("c"+i).innerHTML=document.getElementById("c"+(i-1)).innerHTML;
            }