XUL with HTML

I am trying to create a form using xul and the data to be entered in the mysql database. The way I chose is combining html with xul and use http post method. So for example in my form I have something like:

<html:form action="test.php" method="post" >
... xul stuff here
... xul stuff here

<html:input type="submit" name="submit" value="Login"/>
</html:form>

and then in test.php I could do all database work but for now, in my test.php I have:

echo ("test");


now when I double click on my xul file to run it, it shows me the form and I enter the data and Login - once I login it runs the test.php but it does not show anything. (test) is not shown in this case. however, when I run through http://localhost/xul/test.php it shows (test) on the screen. When I run through http://localhost/xul/myxulfile.xul it prints out just the material of the file on the screen rather than just the execution of the file.


Now. what do you think I need to do in order to have the test.php work when I use myxulfile.xul ? Do I need to change anything in configurations?

Please help!