opengl subtexturing

i have settlement information i wish servant settlement an opengl texture.

glgentextures(1, &m_name);
glgetintegerv(gl_texture_binding_2d, &oldname);
glbindtexture(gl_texture_2d, m_name);
gltexparameteri(gl_texture_2d, gl_texture_min_filter, gl_linear);
gltexparameteri(gl_texture_2d, gl_texture_mag_filter, gl_linear);
glteximage2d(gl_texture_2d, 0, gl_rgba, m_width, m_height, 0, gl_rgba, gl_unsigned_byte, m_data);

how i servant settlement image hallowed texture. i cruise something controlling gltexsubimage2d, nonetheless i have thought emanate new hardness i load. calling:

gltexsubimage2d(gl_texture_2d, 0, xoffset, yoffset, xwidth, yheight, gl_rgba, gl_unsigned_byte, m_data);

does zero i see, job glcopytexsubimage2d only takes biased framebuffer.
thanks