when i click on one checkbox check all checkboxes
function setAllCheckboxes(divId, sourceCheckbox) {
divElement = document.getElementById(divId);
inputElements = divElement.getElementsByTagName('input');
for (i = 0; i < inputElements.length; i++) {
if (inputElements[i].type != 'checkbox')
continue;
inputElements[i].checked = sourceCheckbox.checked;
}
}