$(document).ready(function() {
	$('input:checkbox').click(
		function()
		{
			var classes = $(this).attr('class');
			var classArray = classes.split(' ');

			var maxChecked = $('#' + classArray[1]).val();

			if(maxChecked != -1)
			{
				if(!getNumburOfCheckedCheckboxes(classArray[1], maxChecked))
				{
					alert("Můžete vybrat pouze " + maxChecked + " možnosti!");
					return false;
				}
			}
		}
	);

	function getNumburOfCheckedCheckboxes(checkoxClass, max)
	{
		var checked = $(":checked[class~=" + checkoxClass + "]").length;
		if(checked > max)
			return false;
		else
			return true;
	}
});