i modified it to
///////////////////////////////
#include <acknex.h>
#include <default.c>

///////////////////////////////
var a;

PANEL* pDisplay =
{
pos_x = 10;
pos_y = 10;
digits (10, 10, 5, *, 1, a);
flags = VISIBLE;
}

function main()
{
video_mode=7;
screen_color.blue = 150;
while(1)
{
a = integer(random(13));
if(a = 1)
{
set(pDisplay, VISIBLE);
}
else
{
reset(pDisplay , VISIBLE);
}
wait(-1);
}
}




and now my a == 1 and do not change,why?