Css Div Border Around Child Divs

I have one container div, which contains 3 divs inside it. When i write border:1px solid red for container div, border is shown only on top of these 3 child divs, but not around t

Solution 1:

add overflow:hidden;

#cont {width:800px;margin-right:auto;margin-left:auto; border:1px dashed red;padding:2px; overflow:hidden;}

Solution 2:

<div style="clear:both;float:none;"></div> well solve your problem. added it under the div's

Solution 3:

add overflow:hidden to the #cont element