Thanks Greg.
Maybe make these 'unsigned int' or 'unsigned long'
Gives you the full range for the type. (don't need negative numbers 
):
int intervalOne = 1000; // Interval at which to display (milliseconds)
int intervalTwo = 2000;
int intervalThree = 3000;
example: unsigned long myInterval = 400000UL;
Also this is usually accepted as more correct to prevent slippage:
Accumulator1 = currentMillis;
Change to:
Accumulator1 = Accumulator1 + intervalOne;
etc.
Did this a way back, might find something interesting here:
//Blink without Delay skeleton
//4 examples demonstrated
//LarryD
//LED wiring options
//=============================================
//Depending which way your LEDs are wired, uncomment the next line.
//#define PlusEqualsON
#ifdef PlusEqualsON
//wired so +5V turns LED ON
#define ledON HIGH
#define ledOFF LOW
//=========================
#else
//wired so +5V turns LED OFF
#define ledON LOW
#define ledOFF HIGH
//=========================
#endif
//switch wiring options
//=============================================
//Depending which way your switches are wired, uncomment the next line.
#define PushEqualsLOW
#ifdef PushEqualsLOW
//pushing the switch makes pin LOW
#define Pushed LOW
#define Released HIGH
//=========================
#else
//pushing the switch makes pin HIGH
#define Pushed HIGH
#define Released LOW
//=========================
#endif
//=============================================
unsigned long currentMillis;
unsigned long pin13Millis;
unsigned long pin12Millis;
unsigned long pin11Millis;
unsigned long SwitchMillis;
//if these are not changed in the sketch, they can be const
unsigned long debounceMillis = 100UL; //100ms
unsigned long ledOnTime = 5*1000UL; //5 seconds
byte laststartSwitchState = HIGH;
byte buttonState = HIGH;
byte counter = 0;
//the following are enable/disable flags
//some of these might not be used in this sketch
boolean flag13 = true;
boolean flag12 = true;
boolean flag11 = true;
boolean flag10 = true;
const byte startSwitch = 2; //pushed = LOW
const byte testSwitch = 3; //pushed = LOW
//**********************************************************************
void setup()
{
Serial.begin(9600);
digitalWrite(13,ledOFF);
pinMode(13, OUTPUT);
digitalWrite(12,ledOFF);
pinMode(12, OUTPUT);
digitalWrite(11,ledOFF);
pinMode(11, OUTPUT);
digitalWrite(10,ledOFF);
pinMode(10, OUTPUT);
pinMode(startSwitch, INPUT_PULLUP); //pushed = LOW
pinMode(testSwitch, INPUT_PULLUP); //pushed = LOW
} // >>>>>>>>>>>>>> E N D O F s e t u p ( ) <<<<<<<<<<<<<<<<<
void loop()
{
//save the current time
currentMillis = millis();
//************************************* E x a m p l e 1
//toggle pin 13 every 200mS
//has 200ms or more gone by?
if (currentMillis - pin13Millis >= 200UL)
{
//code here runs every 200ms
//get ready for next iteration
pin13Millis = pin13Millis + 200UL;
//toggle pin 13
digitalWrite(13,!digitalRead(13));
}
//************************************* E x a m p l e 2
//at power up, pin 12 LED goes ON, after 3 seconds goes OFF and stays OFF
//could be used as a powerup reset signal
if (flag12 == true && currentMillis - pin12Millis <= 3000UL)
{
//code here runs for 3 seconds after power up, then stops
digitalWrite(12,ledON);
}
else
{
digitalWrite(12,ledOFF);
//disable further pin 12 control
flag12 = false;
}
//************************************* E x a m p l e 3
//if testSwitch is pushed and released
//pin 11 LED goes ON for 5 seconds, then goes OFF
buttonState = digitalRead(testSwitch);
//are we are allowed to check the switch and is it pressed?
if(flag11 == true && buttonState == Pushed)
{
//enable timing of LED on pin 11
flag11 = false; //false --> timing is enabled
//turn LED ON
digitalWrite(11,ledON);
//record the time LED turned ON
pin11Millis = currentMillis;
}
//are we allowed and is it time to control pin 11
if (flag11 == false && currentMillis - pin11Millis >= ledOnTime)
{
//if enabled, code here runs after ledOnTime ms goes by
digitalWrite(11,ledOFF);
//allow switch press detection again
flag11 = true; //true --> switch monitoring is enabled
}
//************************************* E x a m p l e 4
//is it time to check the switches?
//in particular, pushing startSwitch will turn ON/OFF (toggle) an output pin 10
//is it time to check the switches
if (currentMillis - SwitchMillis >= debounceMillis)
{
//code here runs every debounceMillis ms
//get ready for the next iteration
SwitchMillis += debounceMillis;
//go and check the switches
checkSwitches();
}
//*********************************
//put other non-blocking stuff here
//*********************************
} // >>>>>>>>>>>>>> E N D O F l o o p ( ) <<<<<<<<<<<<<<<<<
//======================================================================
// F U N C T I O N S
//======================================================================
//****************** c h e c k S w i t c h e s ( ) *********************
//switches are checked every debounceValue milli seconds
//no minimum switch press time is validated with this code (i.e. No glitch filter)
void checkSwitches()
{
//re-usable for all the switches
boolean thisState;
//************************************* E x a m p l e Push ON push OFF (toggle)
//check if this switch has changed state
thisState = digitalRead(startSwitch);
if (thisState != laststartSwitchState)
{
//update the switch state
laststartSwitchState = thisState;
//this switch position has changed so do some stuff
//"HIGH condition code"
//switch went from LOW to HIGH
if(thisState == HIGH)
{
//Do some HIGH switch stuff here
}
//"LOW condition code"
//switch went from HIGH to LOW
else
{
//Do some LOW switch stuff here
digitalWrite(10, !digitalRead(10));
//print number of pushes
counter++;
Serial.println(counter);
}
} //END of startSwitch code
//*****************************************
//similar code for other switches goes here
//*****************************************
} //END of checkSwitches()
//**********************************************************************
//======================================================================
// E N D O F C O D E
//======================================================================