Conditional Region for multiple fields

Hi,

I am trying to suppress a row where field CHG_AMT and field TP_DELV_QTY = 0. In my Conditional region code I have entered the following:

<?if:number(CHG_AMT)!=0.00?><?if:number(TP_DELV_QTY)!=0.00?>

<?end if?>

This will suppress the row if either CHG_AMT or TP_DELV_QTY = zero. How do I write it if I want to say if CHG_AMT and TP_DELV_QTY = zero or if CHG_AMT plus TP_DELV_QTY = zero then suppress?

Thanks