Filter an array? not sure what it is called :)

1

I have an array that looks like this:
100_0061.JPG,100_0064.JPG,100_0068.JPG,100_0069.JP G,test.swf,test.fla, test.psd

and the code that is building it:
//jpgs to load
basePath = mdm.Application.path + “presFiles/”
var myFiles:Array = mdm.FileSystem.getFileList(basePath, “.”);
numberOfFiles = myFiles.length

How can I remove fla and psd files and update the length of the array. Or, how can I filter the array to only show swf and jpg files?