polyline()
Produces an SVG "polyline" element.
Syntax
polyline(
   points STRING )
  RETURNS om.DomNode
- points is a 
STRINGdefining the points of the polygon. 
Usage
This function creates a "polygon" SVG DOM element from the parameters.
The points is a string contains a list of X,Y coordinates to draw the shape, in the form
"x1,y1 x2,y2 ...".
Example
DEFINE n om.DomNode
LET n = fglsvgcanvas.polyline("10,10 10,20 20,20")
CALL n.setAttribute(SVGATT_STYLE, "stroke:#660000;")