fix a comment error.

@@ -330,7 +330,7 @@ func (input *BeegoInput) ParseFormOrMulitForm(maxMemory int64) error {
 // Bind data from request.Form[key] to dest
 // like /?id=123&isok=true&ft=1.2&ol[0]=1&ol[1]=2&ul[]=str&ul[]=array&user.Name=astaxie
 // var id int  beegoInput.Bind(&id, "id")  id ==123
-// var isok bool  beegoInput.Bind(&isok, "isok")  id ==true
+// var isok bool  beegoInput.Bind(&isok, "isok")  isok ==true
 // var ft float64  beegoInput.Bind(&ft, "ft")  ft ==1.2
 // ol := make([]int, 0, 2)  beegoInput.Bind(&ol, "ol")  ol ==[1 2]
 // ul := make([]string, 0, 2)  beegoInput.Bind(&ul, "ul")  ul ==[str array]