NanoMouse Keyboard Control Problem

Hey, I'm a bit new to Arduino (a whopping veteran of two weeks), so keep that in mind, and forgive any stupid mistakes/questions of mine. Thank you in advance for your help!

So a few days ago, I hand crafted my very own NanoMouse with an Arduino Nano, two servos and an omniball. I tried a few simple commands such as myservo.writeMicroseconds(1700) just to see if the servos were working, and all was well. Just last night, I decided I wanted to make my mouse controllable by WASD, the keyboard buttons. If I enter one "if" statement, the input works fine, but if I add one or more "else if" statements, it just continues following the first if statement no matter what. For example, if my first if statement was

if (incomingByte=115){
      leftServo.writeMicroseconds(1300);
      rightServo.writeMicroseconds(1700);
      delay(1000);
      stop();

, the next statement, in this case, an "else if" statement, would follow the servo directions for this first if statement no matter what. Here is my code so far. I am also decently new to the forums, so please excuse me if I either missed a post that was already on this subject, or I didn't put this post in the right section. Feel free to ask for more details if I wasn't clear, and thank you again for your help.

#include <Servo.h>

Servo leftServo;
Servo rightServo;
int incomingByte = 0;   // for incoming serial data

void setup() {
  Serial.begin(9600);     // opens serial port, sets data rate to 9600 bps
  leftServo.attach(6);
  rightServo.attach(5);
}

void loop() {

  // send data only when you receive data:
  if (Serial.available() > 0) {
    // read the incoming byte:
    incomingByte = Serial.read();

    // say what you got:
    Serial.print("I received: ");
    Serial.println(incomingByte, DEC);
    if (incomingByte=115){
      leftServo.writeMicroseconds(1300);
      rightServo.writeMicroseconds(1700);
      delay(1000);
      stop();
    }
    else if (incomingByte=119){
      leftServo.writeMicroseconds(1700);
      rightServo.writeMicroseconds(1300);
      delay(1000);
      stop();
    }
    else if (incomingByte=100){
      leftServo.writeMicroseconds(1300);
      rightServo.writeMicroseconds(1300);
      delay(100);
      stop();
    }
    else if (incomingByte=97){
      leftServo.writeMicroseconds(1700);
      rightServo.writeMicroseconds(1700);
      delay(100);
      stop();
    }
  }
}

void stop(){

  leftServo.writeMicroseconds(1500);
  rightServo.writeMicroseconds(1500);
  delay(500);
}
if (incomingByte=115){

That means "Set incomingByte to 115 and if 115 is not zero, execute the IF clause".
You probably meant:

"Execute the IF clause if incomingByte has the value 115."

if (incomingByte==115){

Set =
Compare ==

Thank you so much! That was a much more simple fix than I had initially thought!