change image on mouseover/mouseout

Hello All, today I have been trying to change an image/symbol when I hover over the image

I have tried

My symbol is pink_dot_new.png

Then I add

mouseover

$(this.lookupSelector("pink_dot_new ")).attr("src","images/Pink_dot_light.png");

mouseout

$(this.lookupSelector("pink_dot_new")).attr("src", "images/Pink_dot_light.png");

And

mouseover

$(this.lookupSelector("ImageHolder")).css('background-image', 'url(images/Pink_dot_light.png)');

mouseout

$(this.lookupSelector("ImageHolder")).css('background-image', 'url(images/Pink_dot_light.png)');

I am not sure what I am missing? Can anybody help?