Javascript VB-Like Rounding Function

Here is a pretty nice rounding function I stole from some website, if I could remember which one I would give them full credit. Javascript lacks a nice built in VB like rounding function, but you can roll your own based on this code.

function roundNumber(num, dec) {
var result = Math.round(num*Math.pow(10,dec))/Math.pow(10,dec);
return result;
}