Hi Lisa, I had the same problem on my site.
Basically when the page loads it will look for the property on the command object, so the property that you are binding to has to be in that command. Because that property is in the header and used by all pages you can safely say that it is part of each command so create a common command class with that property and extend it with each of your command classes.
The second problem is that of naming. If you give your command a name then you need to access it by its name
<spring:bind path="myCommand.propertyName"> if you don't you can access it using the default name
<spring:bind path="command.propertyName"> So don't name your command and let all your pages bind using the default name 'command'.
I hope this makes sense.
One other thing, in Spring 2 which is fully backward compatible you don't need to use the bind anymore, they have given you a heap of tags which make life a lot easier and reduce the amount of lines in your jsp code tremendously.
Eg, going by the above example:
<c:out value="${command.propertyName}"/> no binding needed.
Have a look:
http://static.springframework.org/spring/docs/2.0.x/reference/mvc.html#mvc-formtaglib Hope this helps.
Shawn
http://www.whatjar.co.uk