Código HTML:
Ver original<script language="javascript"> function moure_dalt(ID_objecte) {
var objecte_moure = document.getElementById(ID_objecte);
if (parseInt(objecte_moure.style.top) + 10>90){
objecte_moure.style.top = 90;
}else{
objecte_moure.style.top = parseInt(objecte_moure.style.top) + 10;
}
}
function moure(){
var aleatori;
aleatori = Math.floor (Math.random()*4)+1;
if (aleatori==1) {
moure_dalt('objecte');
}
if (aleatori==2) {
moure_dreta('objecte');
}
if (aleatori==3) {
moure_arriba('objecte');
}
if (aleatori==4) {
moure_esquerra('objecte');
}
window.setTimeout("moure()",1);
}
function moure_dreta(ID_objecte) {
var objecte2_moure = document.getElementById(ID_objecte);
if (parseInt(objecte2_moure.style.left) + 10>90){
objecte2_moure.style.left = 90;
}else{
objecte2_moure.style.left = parseInt(objecte2_moure.style.left) + 10;
}
}
function moure_arriba(ID_objecte) {
var objecte3_moure = document.getElementById(ID_objecte);
if (parseInt(objecte3_moure.style.top) - 10<0){
objecte3_moure.style.top = 0;
}else{
objecte3_moure.style.top = parseInt(objecte3_moure.style.top) - 10;
}
}
function moure_esquerra(ID_objecte) {
var objecte4_moure = document.getElementById(ID_objecte);
if (parseInt(objecte4_moure.style.left) - 10<0){
objecte4_moure.style.left = 0;
}else{
objecte4_moure.style.left = parseInt(objecte4_moure.style.left) - 10;
}
}
<div id="cuerpo" style="width:100px; height:100px; background-color: #F5F5DC; border:1px solid #CCCCCC;margin-bottom:10px;z-index:0"> <div id="objecte" style="position: relative; width:10px; height:10px; left:0px; top:0px; background-color: #cccccc; z-index:1"> </div>
Analiza lo que he hecho, no es una solución general depende de la medida del div contenedor y del objeto flotante.
Quim
(Sembla una mosca collonera)