Problems deleting last row of table

I have tried a number of examples to make a button delete the LAST row of a table, but I cannot make it.

This is the script I am currently using, but it only delets the second row. I'm desperate, I don't know where's the mistake. Please help!

var sSubformSOM = "xfa.form.Summary.INTrack.INRecordTable.INRecord.Row1";

var bCalc = true;

var message = "You have reached the maximum number of items allowed.";

var oSubform = xfa.resolveNode(sSubformSOM);

var sParentSOM = oSubform.parent.somExpression;

var sManagerSOM = sParentSOM + "._" + oSubform.name;

var oManager = xfa.resolveNode(sManagerSOM);

var nMinCount = oManager.occur.min;

var nSubCount = oManager.count;

if (nSubCount > nMinCount) {

          oManager.removeInstance(1);

          if (bCalc == true) {

                    xfa.form.recalculate(1);

          }

} else {

          xfa.host.messageBox(message,"Remove Item", 3);

}