function GetXmlHttpObject() {
	var objXMLHttp=null;
	if (window.XMLHttpRequest) {
		objXMLHttp=new XMLHttpRequest();
	}
	else if (window.ActiveXObject) {
		objXMLHttp=new ActiveXObject("Microsoft.XMLHTTP");
	}
	return objXMLHttp;
}
function check_topic(topic_title, forum_id, topic_id) {
	if (topic_title.length < 3) {
		return;
	}
	if (forum_id == '') {
		return;
	}
	topicCheckRequest = GetXmlHttpObject();
	if (topicCheckRequest == null) {
		return;
	}
	topicCheckRequest.onreadystatechange = topic_check_response;
	topicCheckRequest.open('POST', 'similar_topics_posting.php', true);
	topicCheckRequest.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded; charset=UTF-8');
	topicCheckRequest.send('topic_title=' + encodeURI(topic_title) + '&f=' + forum_id + '&t=' + topic_id);
}
function topic_check_response() {
	if (topicCheckRequest.readyState == 4 || topicCheckRequest.readyState == "complete") {
		if (topicCheckRequest.responseText.length >= 3) {
			document.getElementById('similar_head').innerHTML = '&Auml;hnliche Themen:<br />';
			document.getElementById('similar_topics').innerHTML = topicCheckRequest.responseText;
			Fat.fade_element('similar_topics', 30, 1000, '#666666','#D9D9D9');
		}
	}
}