function IsStringEmpty( stk )
	{
		var i, ch, size;
		
		if (! stk) return 1;
		if (stk.length == 0) return 1;
		size = stk.length;
		for ( i = 0; i < size; ++i ) {
			ch = stk[ i ];
			if ((ch != ' ') && (ch != '\n') && (ch != '\t')) {
				break;
			}
		}
		if (i == size) return 1;
		return 0;
	}
	
	function ValidateOrderForm( )
	{
		//type
		var return_value = true;
		var name;
		var contact_info;
		var address;
		
		var form_elem_id_array = new Array( 'name', 'surname', 'tel', 'city', 'street', 'house', 'index', 'note' );
		var form_elem_name_array = new Array( 'Имя Отчество', 'Фамилия', 'Телефон', 'Город', 'Улица', 'Дом, квартира', 'Индекс' );
		
		if (return_value) {
			for ( i = 0; ((i < form_elem_id_array.length) && (return_value)); ++i ) {
				el = document.getElementById( form_elem_id_array[ i ] );
				if (el) {
					if (IsStringEmpty( el.value )) {
						alert( "Пустое поле '" + form_elem_name_array[ i ] + "'");
						return_value = false;
					}
				}
			}
		}
		return return_value;
	}
	
	function CalculateTotalPrice( )
	{
		var i;
		var size;
		var el_array;
		var sum_price;
		
		sum_price = 0;
		el_array = document.getElementsByTagName( 'input' );
		size = el_array.length;
		for ( i = 0; i < size; ++i ) {
			el = el_array[ i ];
			if (el.type == 'text') {
				if (el.id.indexOf( 'order_count_' )!=-1) {
					count = parseInt( el.value );
					key = el.id.substr( el.id.indexOf( 'order_count_' ) + 12 );
					price_elem_name = 'order_price_' + key;
					price_el = document.getElementById( price_elem_name );
					if (price_el) {
						sum_price += parseFloat( price_el.innerText ) * count;
					}
				}
			}
		}
		total_el = document.getElementById( 'total_price' );
		if (total_el) {
			total_el.innerText = sum_price + ' P';
		}
	}