need help w/code

Hi, will someone tell me the correct way to clear these fields.
--------------------------------------------------
php code;
$zero=0;
// if over-payment subtract over-payment from prevbal field and clear misc chgs
else ($rentpaid > $rentdue )
{ $rentdue = $rentpaid - $rentdue. $prevbal = $zero. $latechg = $zero.
$secdep = $zero. $damage = $zero. $courtcost = $zero. $nsf = $zero. }

 

Where is the code

 

php code; VVVVVVVVVVVVVVVVVV

$zero=0;
// if over-payment subtract over-payment from prevbal field and clear misc chgs
else ($rentpaid > $rentdue )
{ $rentdue = $rentpaid - $rentdue.
$prevbal = $zero.
$latechg = $zero.
$secdep = $zero.
$damage = $zero.
$courtcost = $zero.
$nsf = $zero. }

PHP:

 

I want to update the fields to zero and I get message: Parse error - unexpected ';'

 

1) Where's the IF that ELSE is for?

2) why are you doing string additions between assignments? Did you mean for all those periods to be semi-colons?

3) Why the variable for nothing. Zero is zero...

 

This entire snippet does not make any sense.