Javascript String replaceAll

str.replace(/foo/g, "bar")

or

String.prototype.replaceAll = function(str1, str2, ignore) {

return this.replace(new RegExp(str1.replace(/([\/\,\!\\\^\$\{\}\[\]\(\)\.\*\+\?\|\<\>\-\&])/g,"\\$&"),(ignore?"gi":"g")),(typeof(str2)=="string")?str2.replace(/\$/g,"$$$$"):str2);

}

http://stackoverflow.com/questions/2116558/fastest-method-to-replace-all-instances-of-a-character-in-a-string