Why Object doesn' t support this property or method in Javascript?

Recently, I developed the web camera application using Flex 3.

But, a bug from IE browser's cache wasted me about 4 hours. the short description of bug are:

 

I have developed the swf application embeded in my page of SamplePage. aspx. then I updated swf file in the web server directory.

When those job done, I reopen SamplePage. aspx and access swf property using Javascript code. there is exception popup"Object doesn' t support this property or method".

 

To fixed the problem, I make correct, recompile, check syntax both in ActionScript and Javascript, bla... Bla... Bla ..... The exception still exist.

What's happened?

An idea be came up with after I had went home, it may be caused by browser's cache.

Yes, I deleted the browser's cache, then all thing go right.

 

In the case, I sumarize the following check list.

1, Check spelling.

2, Clean the browser's cache before you testing a page.

2. Relax yourself when you have no idea on a bug.