Checking file extensions

Alright, what I'm trying to do is index my site and build a list of files, but I only want files with certain extensions to be indexed and I'm having some wierd results. When I use (where $entry is a file name) if( ereg( "\.html$", $entry ) ) Everything works great, and only files with the html extension are included in my list. But as soon as I add more file types, for example if( ereg( "[\.html|\.htm]$", $entry ) ) as my condition allows files with types .htm, .html, .js, .shtml, .shtm, and more through to be put in the list. Can anyone see something wrong with my re? Thanks for the help. Ben