Java SWT Dialog won't open

I created a jface dialog with SWT.  When I tried to run it, everything was fine until I called a "dialog.open()".

I got the following error:

Exception in thread "main" java.lang.NoClassDefFoundError: org/eclipse/core/commands/common/EventManager

The fix was simple.  I went to this website:

http://www.jarfinder.com/index.php/jars/versionInfo/19775

and I downloaded the commands.jar.

commands-3.3.0-I20070605-0010.jar

download : http://mirrors.ibiblio.org/pub/mirrors/maven2/org/eclipse/core/commands/3.3.0-I20070605-0010/commands-3.3.0-I20070605-0010.jar

md5 hash : e762e07da9f9b4937d119c9800598a8f

size : 103384 bytes

I added the jar to the project and worked like a charm.  Hope this helps someone.