var currentFontSize = 4;

function revertStyles(fontsize){
	currentFontSize = fontsize;
	changeFontSize(0);
}

function changeFontSize(sizeDifference){
	//get css font size
	var rule = getRuleByName("body.fs" + (currentFontSize + sizeDifference));
	if (rule){
		document.body.style.fontSize = rule.style.fontSize;
		currentFontSize = currentFontSize + sizeDifference;
		createCookie("FontSize", currentFontSize, 365);
	}
	return;
	
};

function getRuleByName(ruleName){
	for (i=0; i<document.styleSheets.length; i++){
		var style = document.styleSheets[i];
		var rules = style.cssRules?style.cssRules:style.rules;
		if (rules){
			for (j = 0; j<rules.length; j++){
				if (rules[j].selectorText.trim().toUpperCase() == ruleName.trim().toUpperCase()){
					return rules[j];
				}
			}
		}
	}
	return null;
}

function createCookie(name,value,days) {
  if (days) {
    var date = new Date();
    date.setTime(date.getTime()+(days*24*60*60*1000));
    var expires = "; expires="+date.toGMTString();
  }
  else expires = "";
  document.cookie = name+"="+value+expires+"../../../; path=/default.htm";
}

String.prototype.trim = function() { return this.replace(/^\s+|\s+$/g, ""); };