function font_change(how) {
	var czySaP = document.getElementsByTagName("P");
	var txt = document.getElementById("tresc");
		if(how=='serif') {
			txt.style.font = "Normal 15px Georgia";
			txt.style.lineHeight = "1.3";			
			if(czySaP.length>=1) for(i=0;i<=czySaP.length;i++) {
				czySaP[i].style.font = "Normal 15px Georgia";}
		        }
		else if(how=='font_up'){
			txt.style.font = "Normal 15px Verdana";
			if(czySaP.length>=1) for(i=0;i<=czySaP.length;i++) {
				czySaP[i].style.font = "Normal 15px Verdana";}
			}
		else if(how=='font_down'){
			txt.style.font = "Normal 11px Verdana";
			if(czySaP.length>=1) for(i=0;i<=czySaP.length;i++){
				czySaP[i].style.font = "Normal 11px Verdana";}		
			  }
			  
			  }


function pokaz(id) {
    document.getElementById(id).style.display = "";
}

function ukryj(id) {
    document.getElementById(id).style.display = "none";
}