Introduction
This article will show you how to allow visitors to increase or decrease the text size (font size) on your website using jQuery and CSS step by step. 
Step 1: First we have to create a Web Application.
- Go to Visual Studio 2010. 
- New--> And select the Web Application. 
- Give whatever name you want to. 
- Click OK. 
![img1.gif]()
Step 2: Secondly you have to add a new page to the website.
- Go to the Solution Explorer. 
- Right-click on the project name. 
- Select add new item. 
- Add new web page and give it a name. 
- Click OK. 
![img2.gif]()
![img3.gif]()
Step 3 : In this step add the CSS code inside the <style> tag and place it into the <head> section of your page.
<style type="text/css">
        html
        {
            font-size: 1em;
            font-family: Arial, Helvetica, sans-serif;
            color: #FFCC99;
        }
        body
        {
            background-color: #CC99CC;
        }
        .pixels
        {
            font-size: 16px;
            line-height: 30px;
            margin-bottom: 20px;
            padding: 20px;
            background-color: #666000;
        }
        .point
        {
            font-size: 12pt;
            line-height: 30px;
            margin-bottom: 20px;
            padding: 20px;
            background-color: #666000;
        }
        .em
        {
            font-size: 1em;
            margin-bottom: 20px;
            padding: 20px;
            background-color:#666000;
        }
        .percentage
        {
            font-size: 100%;
            margin-bottom: 20px;
            padding: 20px;
            background-color:#666000;
        }
        .undefined
        {
            margin-bottom: 20px;
            padding: 20px;
            background-color: #666000;
        }
        #changeFont
        {
            position: absolute;
            top: 10px;
            right: 10px;
            background-color:#339966;
            padding: 5px;
        }
        .increaseFont, .decreaseFont, .resetFont
        {
            color: white;
            font-size: 14px;
            float: left;
            margin: 10px;
        }
</style>
Step 4: In this step we have to write the script reference to the aspx page; let us see from where you have to write the script code.
![img4.jpg]()
Right-click on both files respectively -> copy and paste it inside <Head> section of your page; see step 5.
Step 5: Let us see the script code which you have to add inside the <script></script> tags and that will be placed either in <head> section or the <body> section as you prefer.
<script type="text/javascript" src="Scripts/jquery-1.4.1.min.js"></script>
<script type="text/javascript" src="Scripts/Jquery.js"></script>
Step 6: In this step we have to write the JavaScript code which is given below.
<script type="text/javascript" language="javascript">
        $(document).ready(function () {
            // Reset Font Size
            var originalFontSize = $('html').css('font-size');
            $(".resetFont").click(function () {
                $('html').css('font-size', originalFontSize);
            });
            // Increase Font Size
            $(".increaseFont").click(function () {
                var currentFontSize = $('html').css('font-size');
                var currentFontSizeNum = parseFloat(currentFontSize, 10);
                var newFontSize = currentFontSizeNum * 1.2;
                $('html').css('font-size', newFontSize);
                return false;
            });
            // Decrease Font Size
            $(".decreaseFont").click(function () {
                var currentFontSize = $('html').css('font-size');
                var currentFontSizeNum = parseFloat(currentFontSize, 10);
                var newFontSize = currentFontSizeNum * 0.8;
                $('html').css('font-size', newFontSize);
                return false;
            });
        });
</script>
Step 7: In this step you will see the body code of the Default2.aspx page which is given below.
Code:
<body>
    <h1>
        A Sample Demo</h1>
    <div class="pixels">
        Hello and thank you for visiting the Mindcracker Network</div>
    <div class="point">
        The Mindcracker Network with its global headquarters in Philadelphia </div>
    <div class="em">
        PA was founded in 1999 with a single goal in mind - to provide an online platform for Information </div>
    <div class="percentage">
        Technology Professionals to exchange their knowledge and experience
    </div>
    <div class="undefined">
        by teaching and learning from one another by using various interactive online methods such as contributing articles,
    </div>
    <div id="changeFont">
        <a href="#" class="increaseFont">Increase</a> <a href="#" class="decreaseFont">Decrease</a>
        <a href="#" class="resetFont">Reset</a>
    </div>
</body>
 Step 8: In this step we will see the complete code of the Default2.aspx page which is given below.
Code:
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default2.aspx.cs" Inherits="Default2" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>How to Resize Text Using jQuery</title>
<style type="text/css">
        html
        {
            font-size: 1em;
            font-family: Arial, Helvetica, sans-serif;
            color: #FFCC99;
        }
        body
        {
            background-color: #CC99CC;
        }
        .pixels
        {
            font-size: 16px;
            line-height: 30px;
            margin-bottom: 20px;
            padding: 20px;
            background-color: #666000;
        }
        .point
        {
            font-size: 12pt;
            line-height: 30px;
            margin-bottom: 20px;
            padding: 20px;
            background-color: #666000;
        }
        .em
        {
            font-size: 1em;
            margin-bottom: 20px;
            padding: 20px;
            background-color:#666000;
        }
        .percentage
        {
            font-size: 100%;
            margin-bottom: 20px;
            padding: 20px;
            background-color:#666000;
        }
        .undefined
        {
            margin-bottom: 20px;
            padding: 20px;
            background-color: #666000;
        }
        #changeFont
        {
            position: absolute;
            top: 10px;
            right: 10px;
            background-color:#339966;
            padding: 5px;
        }
        .increaseFont, .decreaseFont, .resetFont
        {
            color: white;
            font-size: 14px;
            float: left;
            margin: 10px;
        }
</style>
<script type="text/javascript" src="Scripts/jquery-1.4.1.min.js"></script>
<script type="text/javascript" src="Scripts/Jquery.js"></script>
<script type="text/javascript" language="javascript">
        $(document).ready(function () {
            // Reset Font Size
            var originalFontSize = $('html').css('font-size');
            $(".resetFont").click(function () {
                $('html').css('font-size', originalFontSize);
            });
            // Increase Font Size
            $(".increaseFont").click(function () {
                var currentFontSize = $('html').css('font-size');
                var currentFontSizeNum = parseFloat(currentFontSize, 10);
                var newFontSize = currentFontSizeNum * 1.2;
                $('html').css('font-size', newFontSize);
                return false;
            });
            // Decrease Font Size
            $(".decreaseFont").click(function () {
                var currentFontSize = $('html').css('font-size');
                var currentFontSizeNum = parseFloat(currentFontSize, 10);
                var newFontSize = currentFontSizeNum * 0.8;
                $('html').css('font-size', newFontSize);
                return false;
            });
        });
</script>
<head>
<body>
    <h1>
        A Sample Demo</h1>
    <div class="pixels">
        Hello and thank you for visiting the Mindcracker Network</div>
    <div class="point">
        The Mindcracker Network with its global headquarters in Philadelphia </div>
    <div class="em">
        PA was founded in 1999 with a single goal in mind - to provide an online platform for Information </div>
    <div class="percentage">
        Technology Professionals to exchange their knowledge and experience
    </div>
    <div class="undefined">
        by teaching and learning from one another by using various interactive online methods such as contributing articles,
    </div>
    <div id="changeFont">
        <a href="#" class="increaseFont">Increase</a> <a href="#" class="decreaseFont">Decrease</a>
        <a href="#" class="resetFont">Reset</a>
    </div>
</body>
</html>
Step 9: In this step we will see the design of the Default2.aspx page which is given below.
![img5.jpg]()
Step 10: In this step we are going to run the Default2.aspx page by pressing F5.
![img6.jpg]()
To increase the font of the text click on 'Increase'.
![img7.jpg]()
![img8.jpg]()
To reset the size of the text click on 'Reset'.
![img9.jpg]()
To decrease the size of the text click on 'Decrease'.
![img10.jpg]()
![img11.jpg]()
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