normal_image = new Image();
normal_image.src = "images/Familierecht_gloed.jpg";

mouseover_image = new Image();
mouseover_image.src = "images/Familierecht.jpg";

normal_image3 = new Image();
normal_image3.src = "images/Scheidingsmediation_gloed.jpg";

mouseover_image3 = new Image();
mouseover_image3.src = "images/Scheidingsmediation.jpg";

normal_image4 = new Image();
normal_image4.src = "images/Echtscheiding_gloed.jpg";

mouseover_image4 = new Image();
mouseover_image4.src = "images/Echtscheiding.jpg";


<!-- repeat the 4 lines above for any subsequent images. -->

function swap(){
if (document.images){
for (var x=0;
x<swap.arguments.length;
x+=2) {
document[swap.arguments[x]].src = eval(swap.arguments[x+1] + ".src");
}
}
}