Trouble with manual PWM

[Gerhard]

I ran the following code on a LED but the led doesn't start from zero brightness and end at full brightness. I tried everything and I am running out of idees. Can somebody please advice why the Led doesnt start at zero brightness until full brightness.

[/double aan = 0;
double af=10000;
int i;
portb=0;
set_tris_a(all_in);
set_tris_b(all_out);

for (i =0;i<=100000;++i)
{
aan = aan+0.1;
af = af-0.1;
output_low(pin_b0);
delay_us(af);
output_high(pin_b0);
delay_us(aan);

}]

[PCM programmer]

[Gerhard]

thanks. It seems to work.
Will this be equavalent to a normal PWM output on a port if I just fine tune the frequency?