func ValueFromRequest(r *http.Request, field string) (string, bool) {
	values := r.URL.Query()
	_, exists := values[field]
	return values.Get(field), exists
}
func ValueFromRequest(r *http.Request, field string) (string, bool) {
	values := r.URL.Query()
	_, exists := values[field]
	return values.Get(field), exists
}
// ValueFromRequest returns the value of a field in the http request. The boolean value is
// set to true if the field exists in the query.