# Polygon through ordered set of gliders

From JSXGraph Wiki

### The underlying JavaScript code

```
board = JXG.JSXGraph.initBoard('jxgbox', {axis:true, boundingbox: [-5, 5, 7, -5]});
board.suspendUpdate();
var p = [];
p[0] = board.createElement('point', [-1,2], {size:2,name:''});
p[1] = board.createElement('point', [0,-2], {size:2,name:''});
p[2] = board.createElement('point', [2,1], {size:2,name:''});
graph = board.createElement('curve', board.neville(p),{strokeWidth:5,strokeOpacity:0.5});
gliders = [];
gliders[0] = board.createElement('glider', [-1,0,graph],{size:4});
gliders[1] = board.createElement('glider', [-0.5,-2,graph],{size:4});
gliders[2] = board.createElement('glider', [1,-3,graph],{size:4});
gliders[3] = board.createElement('glider', [1.5,-1,graph],{size:4});
board.createElement('polygon',gliders,{strokeColor:'red'});
board.updateConditions = function() {
var i;
for (i=1;i<gliders.length;i++) {
if (gliders[i].position<gliders[i-1].position) {
gliders[i].coords = new JXG.Coords(JXG.COORDS_BY_USER, gliders[i-1].coords.usrCoords, board);
gliders[i].update();
}
};
}
board.unsuspendUpdate();
```