function numonly() {
	
	if (event.keyCode < 48 || event.keyCode > 57) {
		event.returnValue= false;
	}
	
}

/**
 * Returns the next value or (if eof) the first value
 */
function next(first, last, curr)
{
	return (curr + 1) > last ? first : (curr + 1);
}
function prev(first, last, curr)
{
	return (curr - 1) < first ? last : (curr - 1);
}

// By id :)
function byId(id)
{
	return document.getElementById(id);
}

function toggleDisplay (objId)
{
	var obj = document.getElementById(objId);
	if (obj.style.display == '') {
		obj.style.display = 'none';
		return;
	}
	
	if (obj.style.display == 'none') {
		obj.style.display = 'block';
	}
	else {
		obj.style.display = 'none';
	}
}

function hideSubcategories()
{
	// Submenus by class
	elms = document.getElementsByClassName('subcategorylist');
	for (i = 0; i < elms.length; i++) {
		var elm = elms[i];
		elm.style.display = 'none';
	}	
}

function toggleSubcategory (objId)
{
	var obj = document.getElementById(objId);

	// Submenus by class
	elms = document.getElementsByClassName('subcategorylist');
	for (i = 0; i < elms.length; i++) {
		var elm = elms[i];
		elm.style.display = 'none';
	}

	if (obj.style.display == '') {
		obj.style.display = 'none';
		return;
	}
	
	if (obj.style.display == 'none') {
		obj.style.display = 'block';
	}
	else {
		obj.style.display = 'none';
	}
}