php

ok, i managed to get it to work with this $amount1 = $invoice_amount; $operator = $invoice_operator; $amount2 = $invoice_multiplier; $rvalue = mcalc ($amount1,$operator,$amount2); function mcalc ($amount1,$operator,$amount2) { if($operator==”+”) $result=$amount1+$amount2; else if($operator==”-“) $result=$amount1-$amount2; else if($operator==”x”) $result=$amount1*$amount2; else if($operator==”/”) $result=$amount1/$amount2; return $result; } echo $rvalue;