javascript remove characters from beginning of string
// this will replace the first occurrence of "www." and return "testwww.com"
"www.testwww.com".replace("www.", "");
// this will slice the first four characters and return "testwww.com"
"www.testwww.com".slice(4);
// this will replace the www. only if it is at the beginning
"www.testwww.com".replace(/^(www\.)/,"");