var SizeChanger = {
	defSize: 12,
	minSize: 10,
	maxSize: 20,
	step: 2,
	
	init:function(){
		this.setSize(this.getSavedSize());
	},
	
	inc:function(){
		var s = this.getSize() + this.step;
		if(s <= this.maxSize) this.setSize(s);
	},
	
	dec:function(){
		var s = this.getSize() - this.step;
		if(s >= this.minSize) this.setSize(s);
	},
	
	std:function(){
		this.setSize(this.defSize);
	},
	
	getSize:function(){
		var dbs = document.body.style.fontSize;
		var s = parseInt(dbs.substr(0, dbs.length-2));
		return s;
	},
	
	setSize:function(size){
		this.saveSize(size);
		document.body.style.fontSize = size+'px';
	},
	
	getSavedSize:function(){
		var retVal = this.defSize;
		if(document.cookie){
			var s = document.cookie.indexOf("=")+1;
			var e = document.cookie.indexOf(";");
			if(e==-1) document.cookie.length;
			var v = parseInt(document.cookie.substr(s,e));
			if(v >= this.minSize && v <= this.maxSize) retVal = v;
		}
		return retVal;
	},
	
	saveSize:function(size){
		document.cookie = 'FontSize='+size+";";
	}
	
}
SizeChanger.init();