function validate(field) {
	with (field) {
		if (value == null || value == '') {
			return false;
		}
		return true;
	}
}

function validate_select(field) {
	with (field) {
		if (value == 'Please select...' || selectedIndex == 0 || selectedIndex == '0') {
			return false;
		}
		return true;
	}
}

function validate_at_least_one_part_number(form) {
	with (form) {
		for (var i = 0; i < elements.length; i++) {
			with (form.elements[i]) {
				if (name == 'part_number[]' && value != null && value != '') {
					return true;
				}
			}
		}
		return false;
	}
}

function validate_form(form) {
	with (form) {
		if (!(validate(name)
					&& validate(surname)
					&& validate_select(state)
					&& validate(landline)
					&& validate_select(machine_model)
					&& validate_at_least_one_part_number(form))) {
			alert('You have not filled in all the required fields, they are marked with an asterisk (*).');

			setStyleByClass('P', 'required', 'color', 'red');
			
//			document.write('<style type="text/css" media="screen">.required { color: red; font-weight: bold; }</style>');

/*			var theRules = new Array();
			if (document.styleSheets[1].cssRules)
				theRules = document.styleSheets[1].cssRules;
			else if (document.styleSheets[1].rules)
				theRules = document.styleSheets[1].rules;
*/

			return false;
		}
		return true;
	}
}

function add_row() {
	var spare_parts = document.getElementById('spareparts_table');

	with (spare_parts) {
		var last = null;
		var lastPos = null;

		for (var i = 0; i < rows.length; i++) {
			if (rows[i].innerHTML.indexOf('part_number[]') != -1) {
				last = rows[i];
				lastPos = i;
			}
		}

		if (last != null) {
			var newRow = insertRow(lastPos);
			for (var i = 0; i < last.childNodes.length; i++) {
				var newNode = last.childNodes[i].cloneNode(true);
				newRow.appendChild(newNode);
			}
		}
	}

}