public void addPages() {
   LineStringBuilder sb = new LineStringBuilder();
   sb.appendLine("For each reaction which is selected a single experiment of two ");
   sb.appendLine("lines will be performed. The first line in which the reaction is ");
   sb.appendLine("enabled and the second line in which the reaction is disabled. ");
   sb.appendLine("If you wish to range over only rate variables or initial component ");
   sb.appendLine("populations then just leave this page blank.");
   reactionKnockoutPage = new ReactionKnockoutPage(model);
   reactionKnockoutPage.setHeaderHelp(sb.toString());
   reactionKnockoutPage.setDefaultSelection(false);
   addPage(reactionKnockoutPage);
   initPopsExperPage = new InitPopsExperimentPage(model);
   addPage(initPopsExperPage);
   rateVarExperPage = new RateVariablesExperimentPage(model);
   addPage(rateVarExperPage);
 }