Using keypad to scroll. HELP PLEASE

That code is the one i used when i used an external button.

key = keypad.getKey();
  
  if (key == '*' )
  { 
    {
      ds+=1;
    }
    if (ds >=4)
    {
      ds=1;
    }
    if(ds ==1){
    //write the stuffs required for page 1
    lcd.setCursor(0,0);
    lcd.print("HOME PAGE        ");
    
    lcd.setCursor(0,1);
    lcd.print("T/I= ");
    lcd.setCursor(6,1);
    lcd.print("NOT=  ");
    lcd.noBlink();
    
    
  }
  if (ds == 2){
    //write the stuffs required for page 2
    lcd.setCursor(0,0);
    lcd.print(" Set Interval:   ");
    lcd.setCursor(0,1);
    lcd.print("           ");
    lcd.setCursor(0,1);
    lcd.blink();
 }
  if (ds == 3){
    //write the stuffs required for page 3
    lcd.setCursor(0,0);
    lcd.print("Set No.of Times:");
    lcd.setCursor(0,1);
   
    lcd.print("          ");
    lcd.setCursor(0,1);
    lcd.blink();
  }
    
  }

this is the one i used to try the key '*'
but it just runs one cycle only, i can't scroll multiple times.