Hey 
I'm still learning Arduino on Arduino Mega2560 and i have a problem about ESP8266-01. I found a topic on internet for creating dynamic web server with jQuery and AJAX for ESP8266 NodeMCU. They use these libraries; ESP8266WiFi.h , WiFiClient.h, ESP8266WebServer.h. I think libraries for only works with NodeMCU because when i try compile, i got an error like this "Error compiling for board Arduino/Genuino Mega or Mega 2560." 
Is there any way to use this libraries with Arduino Mega2560 & ESP8266-01 ? 
Here the code. I want use this code with Arduino Mega2560 & ESP8266-01.
Thanks for your answers already.
#include <ESP8266WiFi.h>
#include <ESP8266WebServer.h>
#include <FS.h> //Include File System Headers
const char* htmlfile = "/index.html";
//WiFi Connection configuration
const char *ssid = "circuits4you.com";
const char *password = "password";
#define LED 2
ESP8266WebServer server(80);
void handlePWM(){
String PWM = server.arg("pwm");
int p = 1024 - (PWM.toInt())*10;
Serial.println(p);
analogWrite(LED,p);
server.send(200, "text/plane","");
}
void handleRoot(){
server.sendHeader("Location", "/index.html",true); //Redirect to our html web page
server.send(302, "text/plane","");
}
void handleWebRequests(){
if(loadFromSpiffs(server.uri())) return;
String message = "File Not Detected\n\n";
message += "URI: ";
message += server.uri();
message += "\nMethod: ";
message += (server.method() == HTTP_GET)?"GET":"POST";
message += "\nArguments: ";
message += server.args();
message += "\n";
for (uint8_t i=0; i<server.args(); i++){
message += " NAME:"+server.argName(i) + "\n VALUE:" + server.arg(i) + "\n";
}
server.send(404, "text/plain", message);
Serial.println(message);
}
void setup() {
delay(1000);
Serial.begin(115200);
Serial.println();
pinMode(LED,OUTPUT);
//Initialize File System
SPIFFS.begin();
Serial.println("File System Initialized");
//Connect to wifi Network
WiFi.begin(ssid, password); //Connect to your WiFi router
Serial.println("");
// Wait for connection
while (WiFi.status() != WL_CONNECTED) {
delay(500);
Serial.print(".");
}
//If connection successful show IP address in serial monitor
Serial.println("");
Serial.print("Connected to ");
Serial.println(ssid);
Serial.print("IP address: ");
Serial.println(WiFi.localIP()); //IP address assigned to your ESP
//Initialize Webserver
server.on("/",handleRoot);
server.on("/setLED",handlePWM); //Reads ADC function is called from out index.html
server.onNotFound(handleWebRequests); //Set setver all paths are not found so we can handle as per URI
server.begin();
}
void loop() {
server.handleClient();
}
bool loadFromSpiffs(String path){
String dataType = "text/plain";
if(path.endsWith("/")) path += "index.htm";
if(path.endsWith(".src")) path = path.substring(0, path.lastIndexOf("."));
else if(path.endsWith(".html")) dataType = "text/html";
else if(path.endsWith(".htm")) dataType = "text/html";
else if(path.endsWith(".css")) dataType = "text/css";
else if(path.endsWith(".js")) dataType = "application/javascript";
else if(path.endsWith(".png")) dataType = "image/png";
else if(path.endsWith(".gif")) dataType = "image/gif";
else if(path.endsWith(".jpg")) dataType = "image/jpeg";
else if(path.endsWith(".ico")) dataType = "image/x-icon";
else if(path.endsWith(".xml")) dataType = "text/xml";
else if(path.endsWith(".pdf")) dataType = "application/pdf";
else if(path.endsWith(".zip")) dataType = "application/zip";
File dataFile = SPIFFS.open(path.c_str(), "r");
if (server.hasArg("download")) dataType = "application/octet-stream";
if (server.streamFile(dataFile, dataType) != dataFile.size()) {
}
dataFile.close();
return true;
}