BCGControlBar Pro for MFC
void CBCGPChartVisualObject::ShowAxisGridLines ( int  nAxisID,
BOOL  bShowMajorGridLines = TRUE,
BOOL  bShowMinorGridLines = FALSE 

Shows or hides major and minor grid lines for the specified axis.

nAxisIDSpecifies the axis ID.
bShowMajorGridLinesTRUE - show major grid lines; FALSE - hide major grid lines.
bShowMinorGridLinesTRUE - show minor grid lines; FALSE - hide minor grid lines.