user	browser	server	multiply.php
	render index page
>> click on "Basic Form" >>
	>> get form.htm >>
		locate form.htm
	<< form.html <<
	render form.html
>> enter data >>
>> click calc button >>
	>> get multiply.php?x=5&y=6 >>
		locate mutiply.php
		>> start >>
			get x and y
			calc
		<< 5 + 6 = 30 <<
	<< html - 5+6=30 <<
	render