diff --git a/grmi/Paging.go b/grmi/Paging.go
index 9d8774f..b2395a0 100644
--- a/grmi/Paging.go
+++ b/grmi/Paging.go
@@ -5,8 +5,10 @@ import (
 )
 
 const (
-	PageSize   = "pageSize"
-	PageNumber = "pageNumber"
+	PageSize    = "pageSize"
+	_PageSize   = "_pageSize"
+	PageNumber  = "pageNumber"
+	_PageNumber = "_pageNumber"
 )
 
 type Paging struct {
@@ -33,20 +35,22 @@ func (self *Paging) Fill(urlParameters map[string]string) bool {
 	return false
 }
 
-func getValue(urlParameters map[string]string, name string, defaultValue int64) (int64, bool) {
-	if urlParameter, ok := urlParameters[name]; ok {
-		value, err := strconv.ParseInt(urlParameter, 10, 64)
-		if err == nil {
-			return value, true
+func getValue(urlParameters map[string]string, names []string, defaultValue int64) (int64, bool) {
+	for _, name := range names {
+		if urlParameter, ok := urlParameters[name]; ok {
+			value, err := strconv.ParseInt(urlParameter, 10, 64)
+			if err == nil {
+				return value, true
+			}
 		}
 	}
 	return defaultValue, false
 }
 
 func getPageIndex(urlParameters map[string]string) (int64, bool) {
-	return getValue(urlParameters, PageNumber, 1)
+	return getValue(urlParameters, []string{_PageNumber, PageNumber}, 1)
 }
 
 func getPageSize(urlParameters map[string]string) (int64, bool) {
-	return getValue(urlParameters, PageSize, 10)
+	return getValue(urlParameters, []string{_PageSize, PageSize}, 1)
 }