Javascript regex: How to extract an "id" from a string?

I have this string: `comment_1234` I want to extract the `1234` from the string. How can I do that? Update: I can't get any of your answers to work...Is there a problem with my code? The alert never gets called: ``` var nameValue = dojo.query('#Comments .Comment:last-child > a[name]').attr('name'); alert('name value: ' + nameValue); // comment_1234 var commentId = nameValue.split("_")[1]; // var commentId = nameValue.match(/\d+/)[0]; // var commentId = nameValue.match(/^comment_(\d+)/)[1]; alert('comment id: ' + commentId); //never gets called. Why? ``` Solution: I figured out my problem...for some reason it looks like a string but it wasn't actually a string, so now I am casting `nameValue` to a string and it is working. ``` var nameValue = dojo.query('#Comments .Comment:last-child > a[name]').attr('name'); //comment_1234 var string = String(nameValue); //cast nameValue as a string var id = string.match(/^comment_(\d+)/)[1]; //1234 ```