/*
 * WHO/UNICEF: http://www.babyfriendly.de
 * Copyright (c) 2008 Marco Siegl - email@buerosiegl.com
 * -------------------------------------------------------------------------
 * $Id: fontsize.js, v1.0 2008-02-26 19:26:35 msiegl Exp $
 *
 */

// read current fontsize as param from url and set new!
function setFontSize ( newFontSize ) {

	// get current URL string
	var urlString = location.href;
 	var urlStringLength = urlString.length;

	// search for "fontsize" in current url
	var searchPos = urlString.indexOf("fontsize=");
	var asFirstParam = urlString.indexOf("?fontsize=");
	var firstLength = searchPos-1;

	// if param not found, set default
	if (!newFontSize) { newFontSize = 1; }
	if (searchPos <= 0) { firstLength = urlStringLength; }

	// set appropriate concatenation string
	var urlHasParams = urlString.indexOf("?");
	if ((urlHasParams < 0) || (asFirstParam > 0)) { var concatString = "?"; } else { var concatString = "&"; }

	// split current url: first + param + last
	var first = urlString.substr(0, firstLength);

	if (searchPos > 0) {
		var last = urlString.substr(searchPos-1+11, urlStringLength-searchPos-11+1);
	} else { var last = ""; }

	// concat new urlString
	var newUrlString = first + concatString + "fontsize=" + newFontSize + last;

	// reload page with newFontSize
	top.location.href = newUrlString;
}