Get border width from a div with plain javascript

Question

I got this style applied to a div

div#content {
border: 1px solid skyblue;  
}

and i want to be able to alert the width of the border, I ha

Answer 1

Very old question, but anyway...

This solution is plain JavaScript, and should work in older browsers too. It measures the size of the element, with, and without borders.

The following example should work correctly if the borders around the element are all the same size. If not, the procedure doesn't change much, you just have to set the borders equal to zero, one by one.

var ele=document.getElementById("content");
// measures the element width, WITH borders
var w=ele.offsetWidth;
var cssBackup=ele.style.cssText;
// sets the borders to zero
ele.style.border="0px";
// computes the border size
var bord=(w-ele.offsetWidth)/2;
// resets the css
ele.style.cssText=cssBackup;
alert(bord);