Rotate image with onclick

Question

I try to make a toggle button where my image (an arrow) will be rotated by 180 degrees each click:

Answer 1

This is because the value for rotate angle is absolute, not based on the last rotate.

Working code:

jQuery

var rotate_factor = 0;

function rotateMe(e) {
    rotate_factor += 1;
    var rotate_angle = (180 * rotate_factor) % 360;
    $(e).rotate({angle:rotate_angle});
}

HTML

Update: Shorter code

var rotate_angle = 0;