Ethernet LED Control

if I have this button in the web page
client.println( "<button type=“button” id=“LED2” onclick=“GetButton1()” >LED 13


I want to use this button to control led like this
if (readString.indexOf(“LED2”) > 1)
digitalWrite(13, HIGH); // set pin 4 high
Serial.println(“Led On”);
if(readString.indexOf(“off”) <0)//checks for off
digitalWrite(13, LOW); // set pin 4 low
Serial.println(“Led Off”);
but the problem this button dose not work but this can be work only when i use check box so i need help about this

Define "not work".

Read this before posting a programming question

If you are using a w5100 ethernet shield, pin 13 with the LED is a timing pin for the ethernet chip. Try another pin for the LED.

//zoomkat 10-6-13
//simple button GET with iframe code
//open serial monitor to see what the arduino receives
//use the ' instead of " in html ilnes 
//address will look like when submited
//for use with W5100 based ethernet shields

#include <SPI.h>
#include <Ethernet.h>

byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED }; //ethernet shield mac address
byte ip[] = { 192, 168, 1, 102 }; // arduino IP in lan
byte gateway[] = { 192, 168, 1, 1 }; // internet access via router
byte subnet[] = { 255, 255, 255, 0 }; //subnet mask
EthernetServer server(84); //server port

String readString; 


void setup(){

  pinMode(4, OUTPUT); //pin selected to control
  //start Ethernet
  Ethernet.begin(mac, ip, gateway, gateway, subnet);

  //enable serial data print 
  Serial.println("servertest1"); // so I can keep track of what is loaded

void loop(){
  // Create a client connection
  EthernetClient client = server.available();
  if (client) {
    while (client.connected()) {
      if (client.available()) {
        char c =;

        //read char by char HTTP request
        if (readString.length() < 100) {

          //store characters to string 
          readString += c; 

        //if HTTP request has ended
        if (c == '\n') {

          Serial.println(readString); //print to serial monitor for debuging 

          //now output HTML data header
             if(readString.indexOf('?') >=0) { //don't send new page
               client.println("HTTP/1.1 204 Zoomkat\r\n\r\n");
             else {
          client.println("HTTP/1.1 200 OK"); //send new page
          client.println("Content-Type: text/html");

          client.println("<TITLE>Arduino GET test page</TITLE>");

          client.println("<H1>Zoomkat's simple Arduino button</H1>");
          client.println("<a href='/?on1' target='inlineframe'>ON</a>"); 
          client.println("<a href='/?off' target='inlineframe'>OFF</a>"); 

          client.println("<IFRAME name=inlineframe style='display:none'>");          


          //stopping client

          ///////////////////// control arduino pin
          if(readString.indexOf("on1") >0)//checks for on
            digitalWrite(4, HIGH);    // set pin 4 high
            Serial.println("Led On");
          if(readString.indexOf("off") >0)//checks for off
            digitalWrite(4, LOW);    // set pin 4 low
            Serial.println("Led Off");
          //clearing string for next read


hello , not work the led didn't turn on regrading the second reply this code not works with button ,I want to work the code with button on web page. thanks,

Perhaps the fine folks at could help you with your snippets.