function getHTTPObject() {
	var req;
	req = false;
	// branch for native XMLHttpRequest object
	if(window.XMLHttpRequest) {
		try {
			req = new XMLHttpRequest();
		} catch(e) {
			req = false;
		}
	// branch for IE/Windows ActiveX version
	} else if(window.ActiveXObject) {
		try {
			req = new ActiveXObject("Msxml2.XMLHTTP");
		} catch(e) {
			try {
				req = new ActiveXObject("Microsoft.XMLHTTP");
			} catch(e) {
				req = false;
			}
		}
	}
	return req;
}
var req = getHTTPObject();

function convertTextToHTML(s) {
	s = s.replace(/\&/g, "&amp;").replace(/</g, "&lt;").replace(/>/g, "&gt;").replace(/\n/g, "<br />").replace(/  /g, "&nbsp; ");
	return s;
}

function NovaImagem()
{
	var public_key = "";
	req.open("POST", "/carrega_imagem.php", true);
	req.onreadystatechange = function() 
	{
		if(req.readyState == 4) 
		{
			 document.captcha.src = req.responseText;
			 public_key = req.responseText.replace("./tmp/","/");
			 public_key = public_key.replace(".png","");
			 document.getElementById("public_key").value = public_key;
		}
	};
	
	req.setRequestHeader('Content-Type', 'text/html; charset=iso-8859-1');
	req.send("");
}