// JavaScript Document

var DEFAULT_SIZE = 0.9; // This is the text size in ems. It should be the same as the stylesheet default size.

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

function get_cookie(name) {
    var name_eq = name + "=";
    var ca = document.cookie.split(';');
    for(var i=0;i < ca.length;i++) {
        var c = ca[i];
        while (c.charAt(0)==' ') c = c.substring(1,c.length);
        if (c.indexOf(name_eq) == 0) return c.substring(name_eq.length,c.length);
    }
    return null;
}

function defaultTextSize() {
	thisSize = get_cookie('textSize');
	if( thisSize == null ) {
		thisSize = DEFAULT_SIZE;
	}
	document.write('<style>');
	document.write('#column-middle{');
	document.write('font-size:'+ thisSize + 'em');
	document.write('}');
	document.write('</style>');
}

function textLarger() {
	startSize = get_cookie('textSize');
	if( startSize == null || isNaN(startSize) ) {
		startSize = DEFAULT_SIZE;
	}
	newSize = Number(startSize) + 0.3;
	set_cookie('textSize', newSize);
	document.getElementById('column-middle').style.fontSize = newSize + 'em';
}

function textSmaller() {
	startSize = get_cookie('textSize');
	if( startSize == null || isNaN(startSize) ) {
		startSize = DEFAULT_SIZE;
	}
	newSize = Number(startSize) - 0.3;
	set_cookie('textSize', newSize);
	document.getElementById('column-middle').style.fontSize = newSize + 'em';
}

var currentTextSize = defaultTextSize();