How to round off a calculation to 2 decimal points?

The following is the code for the press button:

on (press) {
var charges:Number = Number(charges_txt.text);
var payments:Number = Number(payments_txt.text);
var resultdivision:Number = payments / charges;
var resultpercentage:Number = resultdivision * 100;
 
if ( isNaN (charges)){
  resultimage_mc.gotoAndStop("error");
  
 }
 else if ( isNaN (payments)){
  resultimage_mc.gotoAndStop("error");
  
 }

 else if (resultpercentage < 67.8) {
  resultimage_mc.gotoAndStop("bad");
  percentage.text = resultpercentage + "%";
 }
 else {
  resultimage_mc.gotoAndStop("good");
  percentage.text = resultpercentage + "%";
 }
}

on the dynamic text labeled PERCENTAGE I cant get it to give me just 2 decimals. What can I add ???