function changeoverview(o) {
		var x = document.getElementById("content");
        x.className="hit1";
		document.getElementById(o).style.display="none";
		//document.getElementById(o).style.backgroundImage="none";
        }
        
function restoreoverview(o) {
		var x = document.getElementById("content");
        x.className="hit2";
		document.getElementById(o).style.display="block";
        }