Watemark to disappear only when user start input in field

Watermark with ajax disappears when field gets focus, which is quite difficult to understand what should I enter in this field if I have not noticed before moving to that field. It's nice to show the water mark until user start entering something into field.

If you have ever used Facebook they are using the same functionality, so let's see how can we do it for our applications.

Easiest way to use the placeholder introduced with HTML5

<input type="text" name="Firstname" placeholder="Enter First name" />
<input type="text" name="Lastname"  placeholder="Enter Last name" />

// For asp.net text box
<asp:TextBox runat="server" id="txtFirstname" MaxLength="50" 
      class="txt-box" placeholder="Enter First name" />    
<asp:TextBox runat="server" id="txtLastname" MaxLength="50" 
      class="txt-box" placeholder="Enter Last name" />

Placeholder property will not be available at design time but once you will render the page it will work smooth without any error. For more detail you should see placeholder attribute on W3c

Since it is a new feature so may not support in user browser, we need to check the browser compatibility if not supported then use the fallback, so let's use jquery and Modernizr to achieve our goal:

<script src="jquery.js"></script>
<script src="modernizr.js"></script>

<script>
$(document).ready(function(){    
if(!Modernizr.input.placeholder){    
    $('[placeholder]').focus(function() {
      var input = $(this);
      if (input.val() == input.attr('placeholder')) {
        input.val('');
        input.removeClass('placeholder');
      }
    }).blur(function() {
      var input = $(this);
      if (input.val() == '' || input.val() == input.attr('placeholder')) {
        input.addClass('placeholder');
        input.val(input.attr('placeholder'));
      }
    }).blur();
    $('[placeholder]').parents('form').submit(function() {
      $(this).find('[placeholder]').each(function() {
        var input = $(this);
        if (input.val() == input.attr('placeholder')) {
          input.val('');
        }
      })
    });    
}    
</script>

Now it will work in every browser, never matter whether you browser is supporting placeholder or not.

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