Logo image and H1 heading on the same line

As example (DEMO):

HTML:

<div class="header">
  <img src="https://stackoverflow.com/questions/11701311/img/logo.png" alt="logo" />
  <h1>My website name</h1>
</div>

CSS:

.header img {
  float: left;
  width: 100px;
  height: 100px;
  background: #555;
}

.header h1 {
  position: relative;
  top: 18px;
  left: 10px;
}

DEMO