function onOpen(e) {
 var n='Run Script';
 var fn='main';
 var m='hello'; // menu name

 var subMenu = [{name: n, functionName: fn}];
 SpreadsheetApp.getActiveSpreadsheet().addMenu(m, subMenu);
}

function main() {
 var sht = "Sheet1";
 var moneycol=5;
 var startrow=2;
 var cols=1;
  
 var ss = SpreadsheetApp.getActiveSpreadsheet();
 var s = ss.getSheetByName(sht);
 var dataRange = s.getDataRange();
 var lastrow = dataRange.getLastRow();
   
 var values = s.getRange(startrow, moneycol,lastrow,cols).getValues();
 var sum = 0;
  
 for (var row in values) {
   for (var col in values[row]) {
      sum += (values[row][col]);
   }
 }

 ss.appendRow(['','','','',sum]);  
}
// end main