function Trim(str,is_global)
{
var result = $.trim(str);
result = str.replace(/(^\s+)|(\s+$)/g,"");
if(is_global != undefined && is_global.toLowerCase()=="g")
result = result.replace(/\s/g,"");
return result;
}
var username=$(‘.name‘).val();
username=Trim(username);
原文：http://www.cnblogs.com/angleyuli/p/4626405.html