Sets the width of the left margin for the background image of a page
Related Variables: DispMgrBMPMarginBottom |DispMgrBMPMarginLeftDispMgrBMPMarginRight |DispMgrBMPMarginsWin |DispMgrBMPMarginTop
Section: System
Default: DispMgrBMPMarginLeft = 0
*No restart required (Settings.Dynamic property)
