You can use this: (depends on what you want):
INSERT INTO table (field1,field2) VALUES (".$Field1.",".$Field2.");
escaped by '' where needed. (Strings)
Now, if you named your variables from a loop (Field1,Field2,Field3,etc...), u use this:
${$Field1};
so you can construct it like this:
$name = "Field$i"; //Asssume $i = 1
$value = ${$name};
value contains the real value from the form.
Hope this helps
fLIPIS