Evaluators - max order for U and V

am drawing meshes using OpenGL evaluators. is there a limit to the order for U and V ?

if i give the value of u2 and v2 greater that 8 , i do not see the mesh. what is the problem ?

i want to use more control points to draw my mesh.

void glMap2f( GLenum target,
GLfloat u1,
GLfloat u2,
GLint ustride,
GLint uorder,
GLfloat v1,
GLfloat v2,
GLint vstride,
GLint vorder,
const GLfloat *points )