Watermark in textbox using JavaScript

In the web application development, developers always try to make UI more user-friendly and interactively. Showing watermark on textbox is one of the tools to increase user-interactivity of website. Most of the sites use the watermark mainly for “Search” functionality. In this post I will show you a simple implementation of watermark in textbox using JavaScript.

So, let’s start the watermark implementation in textbox.

1- Aspx Page

<form id="form1" runat="server">

    <div>

        <asp:TextBox ID="txtWatermarkDemo" runat="server" CssClass="watermark"></asp:TextBox>

    </div>

 </form>

2- CSS styles for watermark and simple textbox

<style type="text/css">

        .watermark

        {

            font-style:italic;

            font-size:12px;

            color:#C0C0C0;

            width:150px;

        }

        .textbox

        {

            font-style:normal;

            font-size:12px;

            color:#000000;

            width:150px;

        }

    </style>

3- JavaScript Code for watermark

<script src="Scripts/jquery-1.4.1.js" type="text/javascript"></script>

<script type="text/javascript">

//function to remove the search keyword when focus is on textbox

        function onFocusWatermark(txtid,strWatermark) {

            var txtval = txtid.value;

            if (txtval == strWatermark) {

                $(txtid).addClass('textbox');

                $(txtid).removeClass('watermark');              

                txtid.value = '';

            }

        }

//function to show the search keyword when leave the textbox empty

        function onBlurWatermark(txtid, strWatermark) {

            var txtval = txtid.value;

            if (txtval == '') {

                $(txtid).removeClass('textbox');

                $(txtid).addClass('watermark');           

                txtid.value = strWatermark;

            }

        }

 </script>

4- Code behind

protected void Page_Load(object sender, EventArgs e)

{

   if (!IsPostBack)

   {

     string strSearch = "Search";

     txtWatermarkDemo.Text = strSearch;

     txtWatermarkDemo.Attributes.Add("onFocus", "onFocusWatermark(this,'" + strSearch + "')");

     txtWatermarkDemo.Attributes.Add("onBlur", "onBlurWatermark(this,'" + strSearch + "')");

  }

}