file dhtmlx_validation.css is missing

hello world
i want to apply a samlpe of basic validation
docs.dhtmlx.com/doku.php?id=dhtm … _assigning
in my html file i wrote

mygrid1 = new dhtmlXGridObject('gridbox'); ... init the grid

mygrid1.enableValidation(true);
mygrid1.setColValidators(“ValidInteger,ValidEmail”);

mygrid1.init();

i insert in the grid the row 1,a is successfully inserted
can some one give me a good examlpe of validation i also tired to use a sample
dhtmlx.com/docs/products/dht … ation.html
but the file i can’t find the file dhtmlx_validation.css

You don’t need dhtmlx_validation.css file to make validation work. This file is included at the sample by mistake.