Required library edition:
Required library file: dhtmlxlayout.js

attaches a status bar to the whole layout or a cell

To the whole layout:

var sb = dhxLayout.attachStatusBar(); // returns status bar object
// setting status bar text
sb.setText("Status Bar");
// getting status bar text
var sbText = sb.getText();

To a cell:

var sb = dhxLayout.cells(id).attachStatusBar();// returns status bar object
sb.setText("Status Bar");
...