Moving cursor in C using atmega16

Question

We're trying to make a project using atmega 16 and C language. The problem is that whenever we want to move a cursor, it goes to random places instead of moving one character right/left. Our first idea was just LCD_command(0x10); for going left. It didn't work although we are sure it should (turning off the cursor works in the same function). We also tried:

uint8_t position = 0;
[...]
void whichButton(){
whatsPressed = keybord();
switch (whatsPressed):
case 1:
{
position = position + 1; 
GoToXY (position, 0);
}
case 2:
{
position = position - 1;
GoToXY (position, 0); //for going left
}
}

Has anybody got any idea how to move it?