Скачать Делаем название поля внутри него

<form name="login" action="#" method="post">
  <div id="username">  
  <label for="username-field" class="overlabel">Имя пользователя...</label>
  <input id="username-field" type="text" name="username" title="Username" value="" tabindex="1" />
  </div>
  <div id="password">
  <label for="password-field" class="overlabel">Пароль...</label>
  <input id="password-field" type="password" name="password" title="Password" value="" tabindex="2" />
  </div>
  <div id="submit">
  <input type="submit" name="submit" value="Войти" tabindex="3" />
  </div>
</form>

<style type="text/css">
form#login {  
position:relative;
}
div#username,
div#password {  
position:relative;  
float:left;  
margin-right:3px;
}
input#username-field,
input#password-field {  
width:10em;
}
label.overlabel {  
position:absolute;  
top:3px;  
left:5px;  
z-index:1;  
color:#999;
}  
label.overlabel {  
color:#999;  
}  
label.overlabel-apply {  
position:absolute;  
top:3px;  
left:5px;  
z-index:1;  
color:#999;  
font-family: Verdana;  
font-size: 11px;  
}
</style>

Шаг 3. "Привязка" основного JavaScript'а

<script type="text/javascript">
  function initOverLabels () {
  if (!document.getElementById) return;  
  var labels, id, field;
  labels = document.getElementsByTagName('label');
  for (var i = 0; i < labels.length; i++) {
  if (labels[i].className == 'overlabel') {
  id = labels[i].htmlFor || labels[i].getAttribute('for');
  if (!id || !(field = document.getElementById(id))) {
  continue;
  }  
  labels[i].className = 'overlabel-apply';
  if (field.value !== '') {
  hideLabel(field.getAttribute('id'), true);
  }
  field.onfocus = function () {
  hideLabel(this.getAttribute('id'), true);
  };
  field.onblur = function () {
  if (this.value === '') {
  hideLabel(this.getAttribute('id'), false);
  }
  };
  labels[i].onclick = function () {
  var id, field;
  id = this.getAttribute('for');
  if (id && (field = document.getElementById(id))) {
  field.focus();
  }
  };
  }
  }
  };
function hideLabel (field_id, hide) {
  var field_for;
  var labels = document.getElementsByTagName('label');
  for (var i = 0; i < labels.length; i++) {
  field_for = labels[i].htmlFor || labels[i].getAttribute('for');
  if (field_for == field_id) {
  labels[i].style.textIndent = (hide) ? '-1000px' : '0px';
  return true;
  }
  }
  }
window.onload = function () {
  setTimeout(initOverLabels, 50);
  };
  </script>