I cannot load texture form file.tga image

const
CubeMapFileName : array[0…5] of String = (‘cm_right.tga’,‘cm_left.tga’,‘cm_top.tga’,
‘cm_bottom.tga’,‘cm_front.tga’,‘cm_back.tga’);

for i := 0 to 5 do
begin
Target := GL_TEXTURE_CUBE_MAP_POSITIVE_X_ARB+i;
LoadTexture(CubeMapFileName[i],Cubemap[i], False, GL_LINEAR, GL_LINEAR_MIPMAP_LINEAR, False);
glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
end;

But this code not completed until I changed file form tga to jpg or bmp.

glTexGenf(GL_S, GL_TEXTURE_GEN_MODE, GL_REFLECTION_MAP_ARB);
glTexGenf(GL_T, GL_TEXTURE_GEN_MODE, GL_REFLECTION_MAP_ARB);
glTexGenf(GL_R, GL_TEXTURE_GEN_MODE, GL_REFLECTION_MAP_ARB);
glEnable(GL_TEXTURE_GEN_S);
glEnable(GL_TEXTURE_GEN_T);
glEnable(GL_TEXTURE_GEN_R);
glEnable(GL_TEXTURE_CUBE_MAP_ARB);

that LoadTexture() function call is suspect.
what you posted is of little help as it is probably a problem with the way you are reading in the image.

check this out:
http://nehe.gamedev.net/data/lessons/lesson.asp?lesson=33