Problem regarding width when using border

I have a issue regarding a div element.

Im using css3 to style the div element .search_container
My problem is that

border:solid 4px #fff

makes the element wider than 100%
Is there a way to make a inner border that dosnt affect the width?

#content .search_container 
	margin:20px 0 0;
	border:solid 4px #fff;
	padding:16px 0;
	-moz-box-shadow:2px 2px 6px rgba(0,0,0,.5);
	-webkit-box-shadow:2px 2px 6px rgba(0,0,0,.5); 

I found the solution - i needed to add these two lines

    -moz-box-sizing: border-box;
    -webkit-box-sizing: border-box;