Question: I have such code:

```
<div style="width:500; height:500;">
    <input type="button"/>
</div>

```

how to fit the button to the div's sizes?
if its imposible ny css, i can use js,jquery

Answer: 
Make sure you give your width and height of parent container a unit suffix on the value:

```
<div style="width:500px;height:500px;">
    <input type="button" style="width:100%;height:100%;"/>
</div>

```
If all you need is getting the button to fill out the div why not remove one of the elements, making either the div act as a button by putting whatever action you want on it's onclick, or just setting the button as the main element with a size.

Might be that you need both, but unless there's a reason you need both, there's no point wrapping the button in a div a you'll just get more elements than needed.