// Checking if zone is regional

function isRegional(zone){
   zone = parseInt(zone,10);
   var isReg = false;

   if((400 <= zone && zone <= 599)|| 
      (1000 <= zone && zone <= 1899)||
      (2000 <= zone && zone <= 2499)||
      (2700 <= zone && zone <= 2999)||
      (3400 <= zone && zone <= 3499)||
      (3600 <= zone && zone <= 3699)||
      (5100 <= zone && zone <= 5399)||
      (5500 <= zone && zone <= 5599)||
      (5700 <= zone && zone <= 5799)||
      (6000 <= zone && zone <= 12899)||
      (13000 <= zone && zone <= 24199)||
      (24300 <= zone && zone <= 25499)||
      (25800 <= zone && zone <= 26899)||
      (27000 <= zone && zone <= 27999)||
      (27200 <= zone && zone <= 27499)||
      (27800 <= zone && zone <= 27999)||
      (42100 <= zone && zone <= 44799)||
      (45700 <= zone && zone <= 45799))
          isReg = true;
          

   return isReg;
}