function isEmail(emailstr)
{
    emailstr=trim(emailstr);
    var emailReg = "^[\\w-_\.]*[\\w-_\.]\@[\\w]\.+[\\w]+[\\w]$";
    var regex = new RegExp(emailReg);
    return regex.test(emailstr);
}

function trim(str)
{
    return str.replace( /^\s*/, "" ).replace( /\s*$/, "" );
}