ATX2 use RC Remote Control for Rescue Robot

#include <ATX2.h>   // ATX2 Board
int ch1,ch2,ch3,ch4;
int x,y,z,a,b;
void setup() {
  XIO();    // ATX2 initialize
  setTextSize(2);
  pinMode(31, INPUT);
  pinMode(30, INPUT);
  pinMode(29, INPUT);
  pinMode(28, INPUT);
}

void loop() {
   ch1=pulseIn(31,HIGH,25000);
   ch2=pulseIn(30,HIGH,25000);
   ch3=pulseIn(29,HIGH,25000);
   ch4=pulseIn(28,HIGH,25000);
 /*  glcd(0,0,"%d ",ch1);
   glcd(1,0,"%d ",ch2);
   glcd(2,0,"%d ",ch3);
   glcd(3,0,"%d ",ch4);*/
   x=map(ch1,1000,2000,-100,100);
   y=map(ch2,1000,2000,-50,50);
   FD2(x+y,x-y);


 }