How to make this HTML code not go to another line
<form>
    <p>Username: </p><input type="text" name="username" />
    <p>Password: </p><input type="text" name="password" />
    <br /><input type="submit" value="Submit" />
</form>

<form>
    <p>Username: <input type="text" name="username" /></p>
    <p>Password: <input type="text" name="password" /></p>
    <br /><input type="submit" value="Submit" />
</form>

<form>
    Username: <input type="text" name="username" />
<br/>
    Password: <input type="text" name="password" />
<br /><input type="submit" value="Submit" />
</form>

<form>
    Username:<br/> <input type="text" name="username" />
<br/>
    Password:<br/> <input type="text" name="password" />
<br /><input type="submit" value="Submit" />
</form>

<form>
  <div style="float: left;">Username: <input type="text" name="username" /></div>
  <div style="float: left;">Password: <input type="text" name="password" /></div>
  <div style="clear: both;"></div>
  <input type="submit" value="Submit" />
</form>

<form>
<p>Username: <input type="text" name="username" /></p>
<p>Password: <input type="text" name="password" /></p>
<p><input type="submit" value="Submit" /></p>
</form>