dialog to select linestyle. Obsolete function.
k=getlinestyle()
This function designed to work with the xset function is also obsolete .Use the property editor ged instead.
getlinestyle opens a graphic window to select a line style.
x=0:0.1:10;
`plot2d`_(x,`sin`_(x))
e=`gce`_(); // store the Compound containing the plot
e.children(1).line_style = getlinestyle();