# Point 'fixed' in one direction

From JSXGraph Wiki

Revision as of 15:08, 8 October 2012 by A WASSERMANN (talk | contribs)

`A` and `B` are free points. Whenever the board is updated, e.g. after a drag event, the x-coordinate of `A` is set to 1 and the y-coordinate of `B` is set to 1. Therefore, `A` moves on a vertical line, `B` moves on a horizontal line.

### The JavaScript code

```
var brd = JXG.JSXGraph.initBoard('jxgbox',{axis:true,boundingbox:[-1,2,2,-1]});
var A = brd.create('point', [1,0]);
var B = brd.create('point', [0,1]);
brd.on('update', function(){
A.moveTo([1, A.Y()]);
B.moveTo([B.X(), 1]);
});
```