js trim

how to trim a string using js?

function trim(str){

 return str.replace(/^\s\s*/, '').replace(/\s\s*$/, '');

}

function trim(str){

 return str.replace(/^\s+|\s+$/g, '');

}

str = trim(str);

jquery:

http://api.jquery.com/jQuery.trim/

str = $.trim(str);

prototype:
http://api.prototypejs.org/language/String/prototype/strip/

str =  str.strip();