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>

```
Why don't you just put the size on the button instead of the div? The div would automatically take on the correct size, and you'll get a perfect fit, without JS.