What follows is a more amusing piece of code that actually does solve something. Specifying a quantity of stuff is a problem that comes up fairly often. Quantities have an amount and a unit, like 3 gallons or 5 feet. As a general rule you want to avoid allowing the user to type anything that will be used as an entry into a database, they will only break your heart (or tables). So selects are preferred to text inputs for pretty much everything. This generates a pair of selects named $prefix.'count' and $prefix.'units' right next to each other.
By this time when you see $ you should think variable. So you know that $prefix means some string that has been assigned to the variable $prefix. You should also think string literal when you see single quotes around some text, like 'count'. So when you see $prefix.'count' you are seeing the contents of the variable $prefix concatenated (.) with the string literal 'count' which results in one string.
Another thing you need to be aware of is that if something isn't a variable and it isn't quoted by either single or double quotes and it isn't an operator (<,>,=,+,-,...) and it looks like some_text($mumble_optional) then it is probably a function. Either one of yours or a PHP built in function. There is a nifty little search feature at the top of the the PHP documentation that defaults to searching the PHP function list. If you see something you don't understand that looks like a function(), go there for enlightenment grasshopper. 
If you find yourself doing the same thing more that once you probably want to try to generalize it an make it into a function. Think of functions as tools that you are building. A few tools that do a a lot of things are better than a lot of tools that each do a few things. They are easier to find if they don't proliferate in an uncontrolled fashion.
A word about comments. PHP supports C style comments, which you don't see in the fragment below. I think comments are an unalloyed good, I just couldn't think of any to add to the code here that aren't blindingly obvious. Maybe I have been doing this too long. I do try to give variables and functions names that have readily apparent meaning.
Another thing I find useful is using text for option values in selects. If you don't specify a value an integer is assigned. Later when you evaluate the value you have an integer with no readily apparent meaning. In the past, integers were the preferred way of carrying value because memory was expensive and we tried to cram as much meaning into each bit as possible. Today memory is cheap, programmer's time is expensive. So any little thing we can do to make things blindingly obvious is a good thing.
Note that we are passing $Ingredient_Count and $Units into the function. This is because we can use the select as both a knob (to adjust things) and an indicator (to inform the user). Without special effort a select shows the first option on the list. We are passing the function the values that we want the select to stick at. If we don't provide values it will do the default behavior. In general we want to design objects that are as broadly useful as possible. This is why we didn't stick any labels on the selects in this function; any that we picked now would probably be wrong. We could pass one in, but it's a complication. Simple and general are what we strive for in functions.
function select_quantity($prefix, $Ingredient_Count, $Units)
{
echo "<select onchange='updateMenu();' name='".$prefix."count' >";
for($i=0.5;$i<5;$i=$i+0.5) {
if($i != $Ingredient_Count) echo "<option value='".$i."'>".$i."</option>";
else echo "<option selected='selected' value='".$i."'>".$i."</option>";
}
for($i=5;$i<33;$i++) {
if($i != $Ingredient_Count) echo "<option value='".$i."'>".$i."</option>";
else echo "<option selected='selected' value='".$i."'>".$i."</option>";
}
echo "</select>";
echo "<select onchange='updateMenu();' value='ea' name='".$prefix."units' >";
if ('ea' != $Units) {echo "<option value='ea'>ea</option>";}
else {echo "<option selected='selected' value='ea'>ea</option>";}
if ('oz' != $Units) {echo "<option value='oz'>oz</option>";}
else {echo "<option selected='selected' value='oz'>oz</option>";}
if ('g' != $Units) {echo "<option value='g'>g</option>";}
else {echo "<option selected='selected' value='g'>g</option>";}
if ('lb' != $Units) {echo "<option value='lb'>lb</option>";}
else {echo "<option selected='selected' value='lb'>lb</option>";}
if ('tsp' != $Units) {echo "<option value='tsp'>tsp</option>";}
else {echo "<option selected='selected' value='tsp'>tsp</option>";}
if ('tbsp' != $Units) {echo "<option value='tbsp'>tbsp</option>";}
else {echo "<option selected='selected' value='tbsp'>tbsp</option>";}
echo "</select>";
}
The first line echos the opening tag of the select assigning the name of the select to be $prefix."count' so we can identify this particular select. The next line is the beginning of a for loop which spans 4 lines. The control structure for the loop increments the temporary variable $i by 0.5 for each pass of the loop. We are doing this because we want the count part of this control to increment by half on the low end till the value 5 and then increment by 1 to 32 which is done in the second for loop. This gives us a finer control of the value on the low end where it is more important and the ability to choose the appropriate units give the user the ability to input any reasonable values for this application. Thinking about reasonable values is part of what you want to do when you design a function. This particular application manages a household inventory. Initially I believed that most of what I was buying was groceries and this select design reflects that. The units are all weights and volumes which are useful in the kitchen and not lengths which are useful other places. After using the program for a bit I would add lengths to this control. I just haven't done it yet because I designed a general purpose work-around into the program that makes this flaw not painful enough to immediately address.
I'd also might add more numbers at the top incrementing by 5 from maybe 30 to 100. There is a limit to how many items you can usefully cram into a select though. One of the ways to manage that is to use a two stage select but that has some interesting complications we will get into later.
The third section of the function generates the units selector. In a select an option has two parts, a value and a label that appears to the user on the select itself. Explicitly calling out the value is not required, if it is absent an integer starting at 0 and incrementing for each additional option is provided. I like to use the same text for the value as the user sees; this way when I encounter the value in the program I know what it does, not just that it is '2'.
Now grab that code above and save it in ~www/tutorial/include/tutorial_functions.php just in front of the closing tag for the PHP at the end of the file. We'll be using this bit shortly. Now we want to rework ~www/tutorial/index.php so that the body looks like:
<body>
<form method="post" action="<?php echo $_SERVER['PHP_SELF']; ?>">
<?php
$debug = true;
if($debug) {$ta = array_keys($_POST);for($ti=0;$ti<count($ta);$ti++) {echo $ta[$ti]."=".$_POST[$ta[$ti]]."<br>";}}
include "include/tutorial_functions.php"; // a collection of functions for various stuff
echo "Hello World...<br />";
echo "Fave Flav:<input type='text' name='favorite_flavor' /> ";
select_command($_POST, $base_name="command"); // pick a command
echo "<br />Food: ";
select_quantity($prefix='food_'); // pick a quantity of food
echo "<br />Drink: ";
select_quantity($prefix='drink_'); // pick a quantity of drink
echo "<input type='submit' name='submit' /> ";
?>
<form>
</body>
So save the files and hit Submit or Reload and pay attention. The first time you hit submit or reload the debug values aren't quite what you expect. Then you hit Submit again and they look OK. This is because the values in the debug area are the values that were on the previous screen. You need to keep that firmly in mind. These things become much more important later. You should now be seeing a screen that looks much like this: 
So who ordered that break between Fave Flave: and Food:? Not what I had in mind. Poking about I notice that the select_command() function emits a <br /> at the end which is affecting our placement of related objects. Do not put positioning stuff in functions, it doesn't belong there. So fix select_command() in include/tutorial_functions.php so it doesn't emit that nasty break and save it away so it works properly. Good.
Another thing you might notice is that I entered 'chocolate => really' into the favorite_flavor text field. That => bit looks dangerously like an operator which ought to scare you. Remember, users can enter anything they can type into a text field and they are not usually looking to make life easy for you. They'll type the darnedest things... Don't give them the chance if you don't have to; if you do, pay attention, there are ways to mitigate the problem.
Another thing that is irritating about this program is that the controls and text inputs are not sticky. The data disappears when you Submit it. Usually that is what we want so that is the default behavior, but not always. Sometimes we want the data to stick. I want it to stick so that's what we'll do next.
