Help

For instructions on the syntax used to enter regular expressions or DFAs/NDFAs, see the Syntax screen (which is accessed from each question page by pressing the Syntax button).

Other problems you may encounter:

1. The applet doesn't load. On any question page, I either see a mostly blank screen or a big gray box. Sometimes the status bar says "Applet Question could not be loaded" or some other non-informative error message.

   There are many things that could cause this. Two are:

   • Your browser doesn't have Java turned on.

     Solution: Go to the options screen (how to do this varies depending on the browser) and turn it on, then reload the page. In Netscape, go to the Edit menu, Preferences..., > Advanced, and click Enable Java. Under MS IE go to Tools, Internet Options, and it's somewhere in there.

   • Your browser doesn't support Java.

     Solution: Upgrade your browser or go use one on a different machine that has a newer browser. Netscape and IE have both supported Java for quite a few years now so this shouldn't be a problem.

   If everything seems fine on your end but the applet still doesn't work, please send email to either the host of this page or the latest listed modifier with as many details as possible about your system, operating system, browser type and release number, and we'll try to figure out what's going on.

2. The applet locks up after a while and I have to kill Netscape (under Unix) or reboot (under Windows) to get the thing working again.

   Solution: This is the fault of the Java virtual machine, which has bugs in many different browser implementations. We have tested the code under known stable VMs and it has been fine for days on end, and on other VMs it causes problems within ten minutes. Unfortunately there doesn't seem to be anything the user can do about it except use a browser or VM that is known to be stable.

3. Sometimes the little popup windows that are created when you press Hint or Syntax won't go away or appear in funny places or do other strange things.

   Solution: Again this seems to be the fault of the Java implementation on whatever platform you're using. Often reloading the page and trying again will clear it up.

4. I swear my answer is right but the #$%!! applet says it's wrong.

   Solution: We have tested this thing against tons and tons of questions and it seems to be pretty good... so chances are your answer is wrong (sorry). However, nothing is ever bug-free.

   If you are currently taking CSC 320 at the University of Victoria (B.C.) and think you found a mistake in any of the solutions, then send a detailed e-mail with a report of the problem to Wendy Myrvold ( wendym@cs.uvic.ca). Bonus marks will be given to the first person to find each error.

5. Other problems?

   Please email us and we'll sort something out.