Untitled

<!DOCTYPE html>
<html>
<head>
<style type="text/css">
body{
background-color:;
}

.skyblue{
background-color:#00FFFF;
float:left;
position:relative;
width:100px;
height:100px;
margin:no margin;
}
.violet{
background-color:violet;
float:left;
position:relative;
width:100px;
height:100px;
margin: no margin;
}
.login{
position:absolute;
width:200px;
height:200px;
top: 50px;
left: 50px;
}
#blocks{
width:400px;
height:400px;
margin:no margin;
}
</style>
</head>
<body>
<div id="blocks">
<div class="skyblue"></div>
<div class="violet"></div>
<div class="skyblue"></div>
<div class="violet"></div>

<div class="violet"></div>
<div class="skyblue"></div>
<div class="violet"></div>
<div class="skyblue"></div>

<div class="skyblue"></div>
<div class="violet"></div>
<div class="skyblue"></div>
<div class="violet"></div>

<div class="violet"></div>
<div class="skyblue"></div>
<div class="violet"></div>
<div class="skyblue"></div>

<div class="login">
Username:
<br><input type="text"></input>
<br>Password:
<br><input type="password"></input>
<br><input type="button" ></input>
</div>

</div>
</body>
</html>