QwtPlotMarker QwtPlotPicker

i am using qwt6.6.0
i have attached 2 vertical markers and 1 horizontal marker to the canvas and attached a picker to plot canvas.I want to move the individual marker and show the label(xpos,ypos)of each .How can i do it??
i am taking the picker pos and setting the marker at that pos ,but not able to distinguish the movements for the each marker.
all markers are moving simultaneously
how to distinguish them

you can move one marker at a time. so, you have one "active" marker. the question is: how do you want to set the active marker? maybe you could use a QComboBox , but there are several other possibilities.