var CurFontSize = null;

function getCookieValue(CookieName){
	if (document.cookie) {
		var StringToFind = CookieName + "=";
		var CookieStart = document.cookie.indexOf(StringToFind);
		if (CookieStart > -1) {
			var CookieValueStart = CookieStart + StringToFind.length;
			var CookieValueEnd = document.cookie.indexOf(";", CookieValueStart);
			CookieValueEnd = (CookieValueEnd > -1)? CookieValueEnd : document.cookie.length;
			var CookieValue = document.cookie.substring(CookieValueStart, CookieValueEnd);
			CookieValue = (CookieValue.length == 0)? null : unescape(CookieValue); 
			return CookieValue;
		}
	}
	return null;
}

function resizeFont(Mode) {
	var DEFAULT_FONTSIZE = 80;
	var FONTSIZE_MAX = 140, FONTSIZE_MIN = 50;
	var RESIZE_STEP = 4;
	var SizeDelta = RESIZE_STEP;
	var NewFontSize;

	if (! CurFontSize) {
		if (document.cookie) CurFontSize = getCookieValue("FontSize");
	}
	if (! CurFontSize) CurFontSize = DEFAULT_FONTSIZE;

	if (Mode == "-") SizeDelta = SizeDelta * -1;

	NewFontSize = parseInt(CurFontSize) + SizeDelta;
	if (NewFontSize < FONTSIZE_MAX && NewFontSize > FONTSIZE_MIN) { 		// setting limits for font-sizes
		document.getElementsByTagName("body")[0].style.fontSize = String(NewFontSize) + "%";
		document.cookie = "FontSize=" + NewFontSize;		// user-FontSize is saved for this session
		CurFontSize = NewFontSize;
	}

	return false;
}