var userAgent = navigator.userAgent.toLowerCase();
var is_opera  = ((userAgent.indexOf('opera') != -1) || (typeof(window.opera) != 'undefined'));
var is_saf    = ((userAgent.indexOf('applewebkit') != -1) || (navigator.vendor == 'Apple Computer, Inc.'));
var is_webtv  = (userAgent.indexOf('webtv') != -1);
var is_ie     = ((userAgent.indexOf('msie') != -1) && (!is_opera) && (!is_saf) && (!is_webtv));
var is_ie4    = ((is_ie) && (userAgent.indexOf('msie 4.') != -1));
var is_ie7    = ((is_ie) && (userAgent.indexOf('msie 7.') != -1));
var is_ps3    = (userAgent.indexOf('playstation 3') != -1);
var is_moz    = ((navigator.product == 'Gecko') && (!is_saf));
var is_kon    = (userAgent.indexOf('konqueror') != -1);
var is_ns     = ((userAgent.indexOf('compatible') == -1) && (userAgent.indexOf('mozilla') != -1) && (!is_opera) && (!is_webtv) && (!is_saf));
var is_ns4    = ((is_ns) && (parseInt(navigator.appVersion) == 4));
var is_mac    = (userAgent.indexOf('mac') != -1);

function getObj(elementid, obj) 
{
	if (typeof obj == 'undefined') 
	{
		obj = document;
	}
	if (obj.getElementById) 
	{
		return obj.getElementById(elementid);
	}
	else if (obj.all) 
	{
		return obj.all[elementid];
	}
	else if (obj.layers) 
	{
		return obj.layers[elementid];
	}
	else 
	{
		return false;
	}
}

function form_focus(text, elm) 
{
	if (elm.value == text)
	{
		elm.value = "";
	}
}

function form_blur(text, elm) 
{
	if (elm.value == "")
	{
		elm.value = text;
	}
}

function form_validate(elms)
{
	var valid = true;
	for (var i = 0; i < elms.length; i++)
	{
		if (getObj(elms[i]).value == '')
		{
			valid = false;
		}
	}
	if (!valid)
	{
		alert('Sie m&uuml;ssen alle Felder ausf&uuml;llen!');
	}
	return valid;
}