ex-preman

function doGet(e) {
    Logger.log(e);
    var op = e.parameter.action;
    var ss = SpreadsheetApp.open(DriveApp.getFileById("YOUR_SPREADSHEET_ID"));
    var sn = "YOUR_SHEET_NAME";
    var sheet = ss.getSheetByName(sn);


    if (op == "insert")
        return insert_value(e, sheet);