how to make this int(random(0,5)) in the code onle randomly choose a number 1 time then stop. I tried to add noLoop() above it, but the followings also stopped loop, that is not what I want. so... please help me. thx, here is the code
PImage[] pstory = new PImage[30];
int j=0;
int s;
PImage k ;
void setup (){
 size (650,800);

for ( int i = 0; i< pstory.length; i++ )
{
pstory[i] = loadImage( i + ".jpg" );}  
}
void draw(){
 println ("j="+j);
if (j>=pstory.length){
 j=0;}else if (j>=3){
   s=int(random (0,5)); I need this one onle run once each time!
   println("s="+s);
   if (s==0){
     j=3;}
    if (s==1){
     j=5;}
      if (s==2){
     j=9;}
      if (s==3){
     j=15;}
      if (s==4){
     j=21;}
 }
 k = pstory [j];
background (k);
}

void mouseReleased(){
   j++;
}