<form>
     <input type="text" id="search-query" />
     <input type="submit" id="search-form-submit" value="Найти" />
</form>

<script type="text/javascript">
var field = document.getElementById('search-query');
searchFieldDefault();
setEventHandler(field, 'focus', searchFieldActive);
setEventHandler(field, 'blur', searchFieldDefault);
document.getElementById('search-form-submit').style.display = 'none';

function setEventHandler(item, event, handler) {
   if (typeof(item.addEventListener) != 'undefined') {
    item.addEventListener(event, handler, false);
   }else if (typeof(item.attachEvent) != 'undefined') {
    item.attachEvent('on' + event, handler);
   }
}
function searchFieldDefault() {
   if (field.value == '') {
    field.value = 'Найти';
   }
   field.style.color = '#B9B9B9';
}
function searchFieldActive() {
   if (field.value == 'Найти') {
    field.value = '';
   }
   field.style.color = '#333333';
}
</script>