I took up an interest in 3dgs and decided to script. its hard...and arduous. but im ready to learn

. i joined Initiate games because the owner is my friend and classmate. I was trying to make a simple counter go from 1 to 17 then to 0 and exit the engine. But... it only goes up to 99 and stops...and does nothing.
here is the code i used
code
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/////////////////////////////////////////////////////////////////
//code by over board - new programmer in Initiate Games /////////
/////////////////////////////////////////////////////////////////
function count_down
{
{
while(cool_var == 10);
{
count += 1;
wait(1);
}
if(count == 17);
{
count -= 1;
wait(1);
}
if(count == 0);
{
exit;
}
}
}