function isMobile()
{
	// primary string match in User Agent; if there is a dependent secondary string,
	var mobileUserAgents = {'iphone':true,'ipod':true,'ipad':true,'android':true,'webkit':{'series60':true,'symbian':true,'palm':true,'webos':true},'blackberry':true};
    return searchList(mobileUserAgents);
}

function isIOS()
{
	// primary string match in User Agent; if there is a dependent secondary string,
	var mobileUserAgents = {'iphone':true,'ipod':true,'ipad':true};
    return searchList(mobileUserAgents);
}

function isAndroid()
{
	// primary string match in User Agent; if there is a dependent secondary string,
	var mobileUserAgents = {'android':true};
    return searchList(mobileUserAgents);
}

function searchList(mobileUserAgents)
{
	var uagent = navigator.userAgent.toLowerCase();
	for (k in mobileUserAgents)
		{
		if (uagent.search(k) > -1)
			{
			if (typeof(mobileUserAgents[k]) == 'boolean')
				{
				return true;
				}
			else
				{
				for (l in mobileUserAgents[k])
					{
					if (uagent.search(l) > -1)
						{
						return true;
						}
					}
				}
			}
		}
	return false;
	}