var agt=navigator.userAgent.toLowerCase();
var is_major = parseInt(navigator.appVersion);
var is_minor = parseFloat(navigator.appVersion);
var is_nav  = ((agt.indexOf('mozilla')!=-1) && (agt.indexOf('spoofer')==-1) && (agt.indexOf('compatible') == -1) && (agt.indexOf('opera')==-1) && (agt.indexOf('webtv')==-1));

var is_nav4 = (is_nav && (is_major == 4));
var is_nav4up = (is_nav && (is_major >= 4));
var is_nav6 = (is_nav && (is_major == 5));
var is_nav6up = (is_nav && (is_major >= 5));
var is_ie   = (agt.indexOf("msie") != -1);
var is_ie3  = (is_ie && (is_major < 4));
var is_ie4  = (is_ie && (is_major == 4) && (agt.indexOf("msie 5.0")==-1));
var is_ie4up  = (is_ie  && (is_major >= 4));
var is_ie5  = (is_ie && (is_major == 4) && (agt.indexOf("msie 5.0")!=-1));
var is_ie5up  = (is_ie && !is_ie3 && !is_ie4);
var is_opera = (agt.indexOf("opera") != -1);
var is_opera4 = (is_opera && (is_major == 4));
var is_opera5 = (is_opera && (is_major == 5));
var is_opera5up = (is_opera && (is_major >= 5));

var is_domcom = ((is_nav6up)||(is_ie5up)||(is_opera5up))
var is_mac    = (agt.indexOf("mac")!=-1);
var is_mac68k = (is_mac && ((agt.indexOf("68k")!=-1) || (agt.indexOf("68000")!=-1)));
var is_macppc = (is_mac && ((agt.indexOf("ppc")!=-1) || (agt.indexOf("powerpc")!=-1)));





/*************************************************
 *	shows element with id passed as parameter
 *************************************************/
/*
function doOver(_id) {
	if (is_domcom) {
		document.getElementById(_id).style.visibility = 'visible';
	} else if (is_ie4){
		document.all[_id].style.visibility = 'visible';
	}
}
*/

/*************************************************
 *	hides element with id passed as parameter
 *************************************************/
/*
function doOut(_id) {
	if (is_domcom) {
		document.getElementById(_id).style.visibility = 'hidden';
	
	} else if (is_ie4){
		document.all[_id].style.visibility = 'hidden';
	}
}

*/

var _timeout	= 500;

function getElementByIds(_id) {

	var _el;

	if(is_domcom) {
		_el	= document.getElementById(_id);
	} else if(is_ie4) {
		_el	= document.all[_id];
	}

	return _el;
}

function _showMenu(_objID) {
	var _obj	= getElementByIds(_objID);
	if(_obj) {
		_obj.style.visibility	= 'visible';
	}
}

function _hideMenu(_objID) {
	var _obj	= getElementByIds(_objID);
	if(_obj) {
		_obj.style.visibility	= 'hidden';
	}
}

/*************************************************
 *	shows element with id passed as parameter
 *************************************************/
function doOver(_id) {

	var _el	= getElementByIds(_id);
	if(_el) {
		if(_el.timer) {
			clearTimeout(_el.timer);
		}
		 _showMenu(_id);
	}
}

/*************************************************
 *	hides element with id passed as parameter
 *************************************************/

var time

function doOut(_id) {

	var _el	= getElementByIds(_id);

	if(_el) {
		var _timer	= setTimeout("_hideMenu('" + _id + "')", _timeout);
		_el.timer	= _timer;
	}
}


function checkForm() {
	if (document.getElementById('name').value == "") {
		alert ('Nezadali ste svoje meno');
		return(false);
	}
	
	else if (document.getElementById('email').value == "") {
		alert ('Nezadali ste svoj e-mail');
		return(false);
	}
	
	else if (document.getElementById('comment').value == "") {
		alert ('Nezadali ste žiadny text správy');
		return(false);
	}
	else return(true);
}