Jak zapętlić by zmianie na przemian ulegał kolor diva ?
<!Doctype html>
<html>
<head>
<title>javascript exercises !</title>
<meta charset="utf-8">
<script type="text/javascript"></script>
<link rel="stylesheet" type="text/css">
</head>
<style>
body{
margin: 0;
width: 100%;
}
#header{
margin: 0;
width: 100%;
height:7vh;
background-color: black;
background-size: 100% 100%;
}
</style>
<body>
<div Id="header" onclick="change_click();"></div>
<script type="text/javascript">
function change_click(){
var div = document.getElementById("header");
if(div.style.backgroundColor="black"){
div.style.backgroundColor="orange";
}
}
</script>
</body>
</html>