ATX2 Control Motor From 4 Channel RC Remote Control

//************************************************
// Control Motor From 4 Channel RC Remote Control
// First Step 2 Channel Only
//************************************************
#include <ATX2.h>
int A,X,Y,Z=0,CH1,CH2,CH3,CH4;

void setup(){
 pinMode(26,INPUT);
 pinMode(27,INPUT);
 pinMode(28,INPUT);
 pinMode(29,INPUT);
}
void loop(){
 CH1 = pulseIn(27, HIGH, 25000);
 CH2 = pulseIn(26, HIGH, 25000);
 if(CH2>1600){
   if(CH1<1400){
       A=map(CH1,1000,1400,100,0);
       motor(12,A);motor(34,-A);
   }
   else if (CH1>1600){
       A=map(CH1,1600,1990,0,100);
       motor(12,-A);motor(34,A);
   }
   else {
       A=map(CH2,1600,1990,0,100);
       motor(12,A);motor(34,A);
   }
 }
  else if(CH2<1400){
   if(CH1<1400){
       A=map(CH1,1000,1400,100,0);
       motor(12,-A);motor(34,A);
   }
   else if (CH1>1600){
       A=map(CH1,1600,1990,0,100);
       motor(12,A);motor(34,-A);
   }
   else {
       A=map(CH2,1000,1400,100,0);
       motor(12,-A);motor(34,-A);
   }
  }
  else{
      if(CH1<1400){
       A=map(CH1,1000,1400,100,0);
       motor(12,A);motor(34,-A);
   }
   else if (CH1>1600){
       A=map(CH1,1600,1990,0,100);
       motor(12,-A);motor(34,A);
   }
   else {
       motor(12,0);motor(34,0);
   }
  }
 CH3 = pulseIn(28, HIGH, 25000);
 CH4 = pulseIn(29, HIGH, 25000);
}
void FD1 (int speed1,int speed2){
  motor(12,speed1);
  motor(34,speed1);
}