function height(){
var MainContentBorder = document.querySelector("div.main .main-content .border");
var MainContentBorderHeight = window.getComputedStyle(MainContentBorder, null).getPropertyValue("height");
document.querySelector("div.main .left-column-background .border").style.height = MainContentBorderHeight;
}
document.addEventListener("DOMContentLoaded", height);
window.addEventListener("resize", height);