text verification
function process() {
if (xmlHttp.readyState == 4 || xmlHttp.readyState == 0) {
code = encodeURIComponent(document.getElementById("captcha_code").value);
xmlHttp.open("POST", "verify.php", true);
xmlHttp.onreadystatechange = handleServerResponse;
xmlHttp.send("code=" + code);
}
}