function getHTTPObject() {
	if (window.ActiveXObject)
		return new ActiveXObject("Microsoft.XMLHTTP");
	else if (window.XMLHttpRequest)
		return new XMLHttpRequest();
	else {      
		alert("Your browser does not support AJAX.");
		return null;   
	}
}

var topicID = "";

function ajax_post(in_topicID) {
	httpObject = getHTTPObject();
    	    	
    	if (httpObject != null) {
		var now = new Date();
				
		topicID = in_topicID;
		
		var fullURL = 'includes/ajax-topics.php?i=' + escape(topicID) + 
			'&ts=' + now.getTime();
    			
		httpObject.open("GET", fullURL, true);
		httpObject.send(null);
		httpObject.onreadystatechange = ajax_post_handler;
	}
}

function ajax_post_handler() {
	if (httpObject.readyState == 4) {
		if (document.getElementById("a_topic_" + topicID).innerHTML == "(View all posts)") {
			document.getElementById("a_topic_" + topicID).innerHTML = "(Hide)";
			document.getElementById("topic_" + topicID).innerHTML = httpObject.responseText;
		} else {
			document.getElementById("a_topic_" + topicID).innerHTML = "(View all posts)";
			document.getElementById("topic_" + topicID).innerHTML = "";
		}
	}
}