Automatically move data from one sheet to another in google docs

i have a spreadsheet that i keep track of tasks i need to do, once complete i enter a date in the last column. What i want is for that completed task to be moved to sheet 2.

At present i have sheet 1 named SUD_schedule and i want the completed row of data to be moved to sheet 2 named SUD_archive. I've looked through the forum posts already and i've tried a variation of scripts but so far no luck. The closest i have come is this script:

function onEdit() {
  var sheet1 = SpreadsheetApp.getActiveSpreadsheet().getActiveSheet();//Original sheet
  var sheet2 = SpreadsheetApp.getActiveSpreadsheet().getSheets()[1];//target sheet
   // to act on only one sheet, check the sheet name here:
  //If it si not first sheet, it will do nothing
  if (sheet1.getSheetName() != "SUD_schedule") {
    return; 
  }
  //Get Row and column index of active cell.
  var rowIndex = sheet1.getActiveRange().getRowIndex();
  var colIndex =  sheet1.getActiveRange().getColumnIndex();

  //If the selected column is 10th and it is not a header row
  if (colIndex == 16 && rowIndex > 1) {
    //Get the data from the current row
   var data = sheet1.getRange(rowIndex,1,1,9).getValues();
   var lastRow2; 
    (sheet2.getLastRow()==0)?lastRow2=1:lastRow2=sheet2.getLastRow()+1;
    //Copy the data to the lastRow+1th row in target sheet
    sheet2.getRange(lastRow2,1,1,data[0].length).setValues(data);
  }
}

Column P (16) is the task complete date, row 1 is frozen and contains column headers.

Can anybody help show where i'm going wrong.

Kind regards Den