Added input for timeframe (supports minutes and hours only). The VWAP lines will not move when changing resolution of the chart, example - when changing from 5 minute candles to 2 hour candles.
The lines will only be accurate when viewing the chart in the same time frame as set in WH, but otherwise it's quite a good approximation with a high period setting in WH (10 or higher). If your period is low (say you're running 3min/3), it is not recommended that you view the chart at other resolutions.