/**
* v cisle s desitou carkou zmeni carku na tecku
*/
function repair_number(num){
	if(isNaN(num)){
		carka = num.indexOf(',');
		res = num.substr(0, carka) + '.' + num.substr(carka+1, num.length - carka - 1);
		return res;
	} else 
		return num;
}


function count_user_value(index){
	/*
	aa = obj.name.split("_");
	index = aa[aa.length-1];
	*/
	var obj = document.getElementById('user_value_' + index);
	var user_value = obj.value;
	/* uprav cislo v pripade desetinne carky */
	user_value = repair_number(user_value);
	
	var weighted_items = 1;
	var itemscount = document.getElementById('items_count_' + index);
	if(itemscount && itemscount.value != 0){
		weighted_items = itemscount.value;
	}

	
	/* zjisti zda jsou zadana kila (to je v pripade zadavani aktivit) */
	var kg = 1;
	var kg_value = document.getElementById('user_kg_value_' + index);
	if(kg_value && kg_value.value){
		kg = kg_value.value;
		kg = repair_number(kg);
	}
	
	var source = document.getElementById('energy_value_' + index);
	
	result = source.value * user_value * kg / weighted_items;
	result = Math.round(result * 1000) / 1000;
	
	var target = document.getElementById('user_result_' + index);
	target.innerHTML = result;
}