The problem is that when i measured the time with a logic analyzer the 5ms was 30ms and the us time was also incorrect.

the real question is how to calculate the delay. This is the code i used:

oid lcdusdelay(int delay)
{
int i;
for(i=0; i<delay; i++);
}


void lcdmsdelay(int delay)
{
int d;
for( d=0; d < delay; d++ )
delay1ms();
}


void delay1ms(void) /* 1ms delay met een 12Mhz kristal.*/
{
int i;
for(i=0; i<1000; i++);
}