function toggleCheckbox(formName, obj, groupPrefix) {
	var form = document.getElementById(formName);
	for(i = 0; i < form.elements.length; i++) {
		if(form.elements[i].type == 'checkbox') {
			if (groupPrefix) {
				if (form.elements[i].id.substr(0,groupPrefix.length)==groupPrefix) {
					form.elements[i].checked = obj.checked;
				}
			} else {
				form.elements[i].checked = obj.checked;
			}
		}
	}
}

function toggleMain(formName, chkBoxName, groupPrefix) {
	var form = document.getElementById(formName);
	var checked = true;
	for(i = 0; i < form.elements.length; i++) {
		var el = form.elements[i];
		if(el.type == 'checkbox' && el.name != chkBoxName) {
			if(el.checked == false) {
				
				if (groupPrefix) {
					if (el.id.substr(0,groupPrefix.length)==groupPrefix) {
						checked = false;
						break;
					}
				} else {
					checked = false;
					break;
				}
				
			}
		}
	}
	form.elements[chkBoxName].checked = checked;
}

function hasItemsToDelete(formName) {
	var form = document.getElementById(formName);
	var checked = false;
	for(i = 0; i < form.elements.length; i++) {
	var el = form.elements[i];
		if(el.type == 'checkbox') {
			if(el.checked == true) {
				checked = true;
				break;
			}
		}
	}
	return checked;
}

function submitIfHasSelected(formName) {
	if (hasItemsToDelete(formName)) {
		if (confirm('Are you sure to delete?')) {
			var obj = document.getElementById(formName);
			if (obj.submit) {
				obj.submit();
			}
		}
		
	}
}