[glenngv]

Is totalsBlock inside the form tag? Can you post a sample of the generated form field tags returned by responseText?

But why not just generate the values of the totals excluding the field tags? Something like this.

100.00|5.00|110.00

And then just split it to get each total and update the corresponding field.

var totals = http_request.responseText.split("|");
if (totals.length==3){ //change 3 to number of totals you are expecting
  //update the corresponding fields
  var frm=document.formNameHere;
  frm.whateverField1.value = totals[0];
  frm.whateverField2.value = totals[1];
  frm.whateverField3.value = totals[2];
}