[php] submission of 1..N variables

[Ekkard Gerlach]

Hi, 

n pairs of variables reach  
my php-programm by submission: 

A0  - B0
A1  - B1
...
An  - Bn

A0 .. An is always set to a value but not
B0 .. Bn. 

The following php-code should recognise 
A0 .. An and should start an action in case
the corresponding Bi is not empty:

if (isset (A1) then   # entrance
{ 
  i=0;
  while( isset($Ai)) {   /* Of course $Ai is not working !!! */
  { 
    if( isset($Bi)) {     /* .. not working , too  */
        action ....
    }
  }
}

I tried a lot with eval , with backticks, ...
but no suceess. 

Anybody an Idea? 

tia
Ekkard
Ax has always a value. Bx not. I want 
to check Bx with a while - loop
to start a modification in case
Bx is not empty.

How can I programm that? 

All my