string ChartIndicatorName	(	long	chart_id,
		int	sub_window,
		int	index
	)

Returns the short name of the indicator by the number in the indicators list on the specified chart window

Parameters

chart_id	Chart ID. 0 means the current chart
sub_window	Number of the chart subwindow. 0 denotes the main chart subwindow
index	the index of the indicator in the list of indicators. The numeration of indicators start with zero, i.e. the first indicator in the list has the 0 index. To obtain the number of indicators in the list use the ChartIndicatorsTotal() function

Returns

The short name of the indicator which is set in the INDICATOR_SHORTNAME property with the IndicatorSetString() function.
To get error details use the GetLastError() function