Guarda, ho un po' improvvisato. Vedo che su FF va, ma non ho IE per provare
codice:
<script>
//global variables that can be used by ALL the function son this page.
var inputs;
var imgFalse = 'images/false.png';
var imgTrue = 'images/true.png';
//this function runs when the page is loaded, put all your other onload stuff in here too.
function init() {
replaceChecks();
}
function replaceChecks() {
//get all the input fields on the page
inputs = document.getElementsByTagName('input');
//cycle trough the input fields
for(var i=0; i < inputs.length; i++) {
//check if the input is a checkbox
if(inputs[i].getAttribute('type') == 'checkbox') {
//create a new image
var img = document.createElement('img');
//check if the checkbox is checked
if(inputs[i].checked) {
img.src = imgTrue;
} else {
img.src = imgFalse;
}
//set image ID and onclick action
img.id = 'checkImage'+i;
//set image
img.onclick = new Function('checkChange('+i+')');
//place image in front of the checkbox
inputs[i].parentNode.insertBefore(img, inputs[i]);
//hide the checkbox
inputs[i].style.display='none';
}
}
}
//change the checkbox status and the replacement image
function checkChange(i) {
if(inputs[i].checked) {
//inputs[i].checked = '';
document.getElementById('checkImage'+i).src=imgFalse;
} else {
//inputs[i].checked = 'checked';
document.getElementById('checkImage'+i).src=imgTrue;
}
inputs[i].click();
}
function checkUncheckAll(check_bok, check_name)
{
for(j=0; j < inputs.length; j++)
{
if(inputs[j].name==check_name)
{
if(check_bok.checked)
{
inputs[j].checked = 'checked';
document.getElementById('checkImage'+j).src=imgTrue;
}
else
{
inputs[j].checked = '';
document.getElementById('checkImage'+j).src=imgFalse;
}
}
}
}
window.onload = init;
//-->
</script>
<input type="checkbox" value="prova_1" name="prova">
<input type="checkbox" value="prova_2" name="prova">
<input type="checkbox" value="prova_3" name="prova">
<input type="checkbox" value="prova_4" name="prova">
<input type="checkbox" value="prova_5" name="prova">
selezione tutto
<input type="checkbox" onClick="checkUncheckAll(this, 'prova')">