yr = tostring(year,"NSE:X####")
vol3_ticker = ticker+yr
vol3 = security(vol3_ticker, timeframe.period, volume, lookahead=barmerge.lookahead_on)
Error
Cannot call 'security' with arguments (series[string], string, series[float], lookahead=const bool); available overloads: security(string, string, series[float], const bool, const bool, string) => series[float]; security(string, string, series[integer], const bool, const bool, string) => series[integer]; security(string, string, series[bool], const bool, const bool, string) => series[bool]; security(string, string, series[color], const bool, const bool, string) => series[color]; security(string, string, , const bool, const bool, string) =>