var previousSelection = null;
    //Image Groups
    var FAX = '0';
    var SKIP = '1';
    var NONE = null;
  
    //Image States
    var UP = '0';
    var DOWN = '1';
  
    /* Set nested array in following format
     * 0 = up
     * 1 = down
     */
    var jimages = [
      ['images/faxgrey.gif', 'images/faxblue.gif'],
      ['images/skiptracegrey.gif', 'images/skiptraceblue.gif']
      
    ];
  
    function revert(){highlight(previousSelection);}
  
    function select(selection){
      highlight(selection);
      switch(selection){
        case '0':
          previousSelection = FAX;
          break;
        case '1':
          previousSelection = SKIP;
          break;
        default:
          previousSelection = null;
          break;
      }
    }
  
    function highlight(selection){
      //set all tabs to thier respective up -- inactive state
      document.Skiptrace.src= jimages[eval(SKIP)][eval(UP)];
      document.Faxforget.src= jimages[eval(FAX)][eval(UP)];
      //set the the selected tab to its down -- active state
      switch(selection){
        case '0':
          document.Faxforget.src = jimages[eval(FAX)][eval(DOWN)];
          break;
        case '1':
          document.Skiptrace.src = jimages[eval(SKIP)][eval(DOWN)];
          break;
        default:
          break;
      }
  }