I am not able to solve this problem

Two fixed straight line OX and OY are cut by a variable line in the points A and B respectively and P and Q are feet of perpendiculars drawn from A and B upon the lines OBY and OAX. Show that if AB pass through a fixed point, then PQ will also pass through a fixed point.

What I am doing is

I am considering OX and OY as axes.

Thanx for advance