Help Programing the Sharp GP2D120

So i’ve been messing around with my arduino and i’ve been trying to do something simple that will better help me understand to to eventually build the robot i want to build.

Right I have the Sharp GP2D120 mounted to a servo, in the program i thought i had it set so that the sharp would take a reading and then either turn the servo it is mounted on in one direction or another based on the reading. However no matter what i do it just goes back and forth between center and the side it’s supposed to go to when the reading wasn’t close enough.

Here is the code i used. Any help would be greatly appreciated.

#include <Servo.h>

#define IR 0
Servo myservo;
int distance = 0;

void setup()
{
pinMode(IR, INPUT);
myservo.attach(9);
}

void loop()
{
myservo.write(90);
delay(1000);
analogRead(IR);
delay(2000);
if (IR <= 18)
{
myservo.write(180);
delay(1000);
return;
}
else {
myservo.write(0);
delay(1000);
return;
}
}

ps i realize that this is probably completely wrong, but it’s my first time. Be gentle

This isn't a hardware problem. Cross-posting is not the way to get answers, either.