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;   
		}
	}
	
	function validate() {
		id_twitter_username = document.getElementById('twitter_username').value;
		id_auto_follow = document.getElementById('auto_follow').checked;
		id_message = encodeURIComponent(document.getElementById('message').value);
		id_redirect_url = encodeURIComponent(document.getElementById('redirect_url').value);
		
		if(id_twitter_username ==""  || id_message =="" || id_redirect_url =="") {
			alert("Please fill out each field in the form to generate your viral tweets code");
		} else {
			return true;
		}
	}
	
	function generate() {
		//location.href="#retweet_form";
		document.getElementById('code_section').style.display="block";
		if(validate()) {
			generateCode('generate');
		}
	}
	
	function preview() {
		//location.href="#retweet_form";
		document.getElementById('preview_section').style.display="block";
		if(validate()) {
			generateCode('preview');
		}
	}
	
	function generateCode(todonext) {
		id_twitter_username = document.getElementById('twitter_username').value;
		id_auto_follow = document.getElementById('auto_follow').checked;
		id_message = encodeURIComponent(document.getElementById('message').value);
		id_redirect_url = encodeURIComponent(document.getElementById('redirect_url').value);
		
		url = "./includes/gc.php?twitter_username=" + id_twitter_username + "&auto_follow=" + id_auto_follow + "&message=" + id_message + "&redirect_url=" + id_redirect_url;
		httpObject = getHTTPObject();   

		if (httpObject != null) {
			httpObject.open("GET", url);
			httpObject.send(null);
	        httpObject.onreadystatechange = function() {
				if (httpObject.readyState == 4){
					code = httpObject.responseText;
					//alert(code);
					if(todonext=="preview") {
						document.getElementById('preview_section_content').innerHTML = code;
					} else {
						document.getElementById('retweet_code').value = code;
					}
			    }
			};
		}
	}