Change image on click

Hi Experts,

The code below should toggle two images. When the page is run on the first click the image changes but it then does not change on any more clicks.

function ChangeImage(){

imageSrc = document.getElementById('ToDo2').getAttribute("src");
               
                    if (imageSrc == "/images/tickred.jpg") {
                        document.getElementById('ToDo2').setAttribute("src", "/Images/tickGreen.png");
                    }

                    if (imageSrc == "/images/tickgreen.png") {
                        document.getElementById('ToDo2').setAttribute("src", "/Images/tickRed.jpg");
                    }

}

I know one image is a jpg and one a png.