function contactShow(hideIn, show) {
	var childs = document.getElementById(hideIn).getElementsByTagName('div');	//childNodes
	for (var n=0; n<childs.length; n++) {
		document.getElementById(childs[n].id).style.display = 'none';
	}
	document.getElementById(show + '_ans').style.display = 'block';
	document.getElementById(show).checked = true;
}

function resizeRightCorn() {
	 var hgt=document.getElementById('middle_cell').offsetHeight;
	 document.getElementById('left_corn').style.height=hgt+'px';
	 document.getElementById('right_corn').style.height=hgt+'px';
}

function checkForm(form) {
	for (var n=0; n < form.elements.length; n++) {
		if (form.elements[n].title != '' && form.elements[n].value == '') {
			alert('Please fill ' + form.elements[n].title + ' field.');
			return false;
		}
	}
	return true;
}