Trying to cycle images but not updating after first click

It also increments up and down at random intervals. I'm new to javascript and can't figure out what's wrong with it.

var image = 1;

function nextI() {
  image = image + 1;
  console.log(image);
  if (image = 2) {
    document.getElementById("feature").src = "lazD.jpeg";
  } else if (image = 1) {
    document.getElementById("feature").src = "lazC.jpeg";
  } else {
    document.getElementById("feature").src = "lazH.jpeg";
  }
}

function prevI() {
  image = image - 1;
  console.log(image);
  if (image = 2) {
    document.getElementById("feature").src = "lazD.jpeg";
  } else if (image = 1) {
    document.getElementById("feature").src = "lazC.jpeg";
  } else {
    document.getElementById("feature").src = "lazH.jpeg";
  }
}