function checkAll(objForm){
	len = objForm.elements.length;
	var i=0;
	for( i=0 ; i<len ; i++) {
		if (objForm.elements[i].type=='checkbox') {
			objForm.elements[i].checked=objForm.check_all.checked;
		}
	}
}  

function switchSubMenu(){
	if(document.getElementById('subMenu').style.display == '' || document.getElementById('subMenu').style.display == 'none'){
		document.getElementById('subMenu').style.display = 'block';
		document.getElementById('expand').innerHTML = '-';
	}
	else{
		document.getElementById('subMenu').style.display = 'none';
		document.getElementById('expand').innerHTML = '+';
	}
}