Question about LED +SERVO

How do I make an LED go through a blink cycle only once in a loop while operating servos at the same time?

Might need some details on what "while operating servos at the same time". Why is the LED important to the servos; how are the functionally related?

Considering that your servos are doing something repetitive in a loop like moving one way and then moving back where they started… why not just turn the LED on at the top of the loop and turn it off when you change direction?

void loop() {
 digitalWrite(led, HIGH);   // turn the LED on (HIGH is the voltage level)

 for(pos = 0; pos < 180; pos += 1)  // goes from 0 degrees to 180 degrees 
 {                                  // in steps of 1 degree 
   myservo.write(pos);              // tell servo to go to position in variable 'pos' 
   delay(15);                       // waits 15ms for the servo to reach the position 
 }           


 digitalWrite(led, LOW);    // turn the LED off by making the voltage LOW

 for(pos = 180; pos>=1; pos-=1)     // goes from 180 degrees to 0 degrees 
 {                                
   myservo.write(pos);              // tell servo to go to position in variable 'pos' 
   delay(15);                       // waits 15ms for the servo to reach the position 
 } 

}

(edited)

@systemslave: Please read Nick Gammon's posts at the top of this Forum, especially on the use of code tags when you post source code. Also, pressing Ctrl-T on the source before posting puts the code in a standard C style that makes it easier for everyone to read.

systemslave I've tried that but the directions I program aren't the same duration so the LED doesn't blink at the same time and I want it to blink at the same time apart only 1 time through the entire loop.
P.S. The amount of time I want it to blink is = to the amount of time it takes to go through a cycle of the servo. Since I detach the servos(via motor.detach) I want to detach the LED the same time I detach the servos.

I need a bit more info then on the code you are using. Specifically what triggers the servo motion. If the servo motion is tied to human input then there may be no way to know the exact duration of servo movement, and therefore no way to exactly divide it in half before it has been completed. If the duration of servo motion is known prior to the movement you can divide it in half and get a reasonable half cycle blink. You could easily just set an LED to blink while the servo is active and stop when the servo is inactive. It is the half cycle concept that is in question.