You can pass more than one parameter by using
xmlhttp
.send("files=" + files.value + "&tagcount="
+ tagcount.value);
Here files and tagcount are the id of the parmeters to be passed. This was working for my Ajax Script. In normal cases you can just add the parameters by &. So the parameters can look like
"parameter1=" + parameter1.value + "¶meter2=" + parameter2.value