A handy regular expression

Often I need to find a substring which can be easily done with a regular expression.

I find regular expressions really useful once I worked it out, but invaribly it takes me longer to work it out than to use substr or something similar

Hopefully this snippet will be handy for someone else, or at the very least a reference for me the next time I need to do it and have forgotten how it's done.

So, for example if my string is:
var videoName:String = "assets/videos/video_235.flv";
and I need to find the number of it (235) then a quick and easy way is to use a regular expression such as:
var regEx:RegExp = /assets\/videos\/video_([^;]+).swf/
trace(regEx.exec(videoName)[1]);
will display 235
The handy bit is:
([^;]+)

This will get the regex to return everything inbetween what you put infront and behind it.
The backslashes I used are just to escape the forward slashes in the url.