function mainImgPreloader(){
	var i = 0;
	imageObj = new Image();

	mainImages = new Array();
	mainImages[0]="img/main_header_firma.png";
	mainImages[1]="img/main_header_televize.png";
	mainImages[2]="img/main_header_telefon.png";
	mainImages[3]="img/main_header_portal.png";
	mainImages[4]="img/main_header_default.png";

	for(i = 0; i < mainImages.length; i++){
		imageObj.src=mainImages[i];
	}
}

function whichBrs() {
var agt=navigator.userAgent.toLowerCase();
if (agt.indexOf("opera") != -1) return 'Opera';
if (agt.indexOf("staroffice") != -1) return 'Star Office';
if (agt.indexOf("webtv") != -1) return 'WebTV';
if (agt.indexOf("beonex") != -1) return 'Beonex';
if (agt.indexOf("chimera") != -1) return 'Chimera';
if (agt.indexOf("netpositive") != -1) return 'NetPositive';
if (agt.indexOf("phoenix") != -1) return 'Phoenix';
if (agt.indexOf("firefox") != -1) return 'Firefox';
if (agt.indexOf("safari") != -1) return 'Safari';
if (agt.indexOf("skipstone") != -1) return 'SkipStone';
if (agt.indexOf("msie") != -1) return 'Internet Explorer';
if (agt.indexOf("netscape") != -1) return 'Netscape';
if (agt.indexOf("mozilla/5.0") != -1) return 'Mozilla';
if (agt.indexOf('\/') != -1) {
if (agt.substr(0,agt.indexOf('\/')) != 'mozilla') {
return navigator.userAgent.substr(0,agt.indexOf('\/'));}
else return 'Netscape';} else if (agt.indexOf(' ') != -1)
return navigator.userAgent.substr(0,agt.indexOf(' '));
else return navigator.userAgent;
}


function changeMainBackground(imgName){
document.getElementById('tableMainHeader').style.background = "url('img/main_header_"+ imgName +".png') no-repeat";
}

function scrollDivs(){

navigatorName = whichBrs()

	if(document.getElementById('divTierInfo')){

		switch(navigatorName){
			case "Safari":
  				divTop = document.body.scrollTop + 'px';
				document.getElementById('divTierInfo').style.top = divTop;
		  		break;
			default:
				divTop = document.documentElement.scrollTop + 'px';
				document.getElementById('divTierInfo').style.top = divTop;		
		}

	}

}