using variables from a form in a longish script - outside of functions

in a longish script I have variables coming in from a form like this: A user fills in username & password and action calls the script - the variable values are passed to the script - so far this works. Now when e.g. I want the user to add a new record (which is the purpose of the script) the variables (that echoed their passed over values in the beginning of the script) are empty when used further down. Though there is no function involved (where I could define the variables as global ), only a if-statement within which the variables are used. Any clues? Thanks everybody. Helmut Why dont I get the values