Monday, November 14, 2011

A Simple Page Layout with CSS

Read the article below by NRJ Design.  Answer the questions as comment posts!

How to build a basic CSS layout
Designing without tables by using CSS layouts is fast becoming the new standard on the Web because of the many benefits it offers. Web browsers used these days are now able to render web pages proficiently. In this article I will endeavor to create a basic 2 column CSS layout which you can use for future design projects.
Here is the link to the Basic CSS layout.
1. Divide your page into sections - the tags allows you to create distinct divisions on your web page.
They are identified with a unique id. You can then add a style (css selector) that specifically applies to the div of that id. Remember to include the DOCTYPE (to render your page accurately in the browsers) and meta tags (enables search engines to spider your pages).
wrapper: is the div that wraps around all the other divs like a container for the page elements.
header: defines the top banner of the page
main: defines the main content of the page
nav: defines the navigation of the page
footer: defines the footer and sub-navigation of the page
<!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">
< html>
< head>
< title>How to Build a Basic CSS Layout</title>
< meta name="Description" content="How to Build a Basic CSS Layout" />
< meta name="Keywords" content="css layout" />
< meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
< /head>
< body>
< div id="wrapper">
< div id="header"></div>
< h1>Basic CSS Layout</h1>
< div id="nav"></div>
< h2>Navigation</h2>
< div id="main"></div>
< div id="footer"></div>
< /div>
< /body>
< /html>

2. Create the CSS code - below is the CSS code that styles the page as a centered 2 column CSS layout with a navigation bar and a footer. The div#wrapper style creates the centered box which acts as a container for the rest of the page content. The width: 80% rule sets the width of the div. The background-color:#FFFFFF rule creates a white background for the div. The margin-top: 50px and margin-bottom: 50px rules create a space of 50 pixels for the top and bottom margins for the div itself.
The proper way to center a block-level element with CSS is to set margin-left: auto and margin-right: auto. This instructs the browser to automatically calculate equal margins for both sides, thus centering the div. The border: thin solid #000000 rule adds a border around the outer div. The rest of the CSS code styles the divs for the header, footer, nav, and main content.
The div#header and div#footer styles set margins and padding for those divs. In addition, div#header includes the text-align: center rule to center the header text, and div#footer includes the border-top: thin solid #000000 rule to create a border along the top edge of the div to replace the horizontal rule above the footer in the table-based layout.
The div#nav and div#main styles create the two columns in the middle of the centered box. In the div#nav style, the float: left rule pushes the div to the left side of its parent element (the wrapper div), and the width: 25% rule sets the div's width to 25 percent of the parent element. With the nav div floated to the left and limited to a set width, it leaves room for the main div to move up to the right of the nav div, thus creating the two-column effect. The div#main style includes the margin-left: 30% rule to keep the main text aligned in a neat column instead of spreading out below the nav column. The main div's left margin is set to a value slightly larger than the width of the nav div.
<style type="text/css">
< !--
body {
background-color: #999999;
font-size:12px;
font-family:Verdana, Arial, Helvetica, sans-serif;
}
div#wrapper {
width: 80%;
background-color:#FFFFFF;
margin-top: 50px;
margin-bottom: 50px;
margin-left: auto;
margin-right: auto;
padding: 0px;
border: thin solid #000000;
}
div#header {
padding: 15px;
margin: 0px;
text-align: center;
}
div#nav {
width: 25%;
padding: 10px;
margin-top: 1px;
float: left;
}
div#main {
margin-left: 30%;
margin-top: 1px;
padding: 10px;
}
div#footer {
padding: 15px;
margin: 0px;
border-top: thin solid #000000;
}
-->
< /style>
3. Create the side navigation menu - to build the left side navigation I use the normal CSS code for the different links ie
a:link {
text-decoration: none;
}
a:visited {
text-decoration: none;
}
a:hover {
text-decoration: underline;
color: #FF0000;
}
a:active {
text-decoration: none;
}
If links are placed elsewhere on the page they will inherit the same properties as above..a blue link that hovers to red.
What if you wish to create another set of different colored links that change color and are underlined when your mouse passes over them?
4. Create the bottom navigation - to include the navigation in the <div id="footer"> section of the page, I use div#footer and code each link accordingly. To make the list go horizontally I use: display: inline;
div#footer ul li{
color : #000000;
background-color : transparent;
display: inline;
}
div#footer ul li a{
color : #115EAC;
background-color : transparent;
text-decoration : none;
}
div#footer ul li a:hover{
text-decoration : underline;
}
-->
Now that I have finished creating my style sheet I want to shorten the code on page by linking it to my external style sheet. Here's how:
5. Create an external style sheet - copy and paste all the css code (without these tags: <style type="text/css"><!-- --></style>) into notepad and name it something like "style sheet". Place this style sheet between the head tags of your web page like this:
<head>
< link rel="stylesheet" href="stylesheet.css" type="text/css" />
< /head>
This will reduce the code on your page so it will load fast plus the search engines can more easily spider your web page.
6. Add content to your page - after you have got your page looking correctly, you can add more content to it. Adjustments can easily be made to any style on the page (or your whole site) by simply editing one style sheet.
7. Upload your files - be sure to upload your web pages and style sheet to the root directory of your server.

8. Validate your code - be sure to validate your xhtml code: http://validator.w3.org/ and css code: http://jigsaw.w3.org/css-validator/ and make corrections where necessary.
9. Check browser compatibility and screen resolution - check that your page renders well in the popular browsers (IE6, NN7, Firefox)
If you are beginning with CSS layouts, implement then slowly by making small changes to your pages i.e. creating a style sheet for your main headers and fonts only. As you become more familiar with CSS you may eventually build all your future sites with CSS layouts.

Question 1.  What is the purpose of the wrapper div in the above example.?


Question 2. How would you center the wrapper div container?


Question 3. What does the CSS display:inline attribute do the list items in step 4?


Question  4. Why does using an external style sheet give you more flexibility for format your web site?

Tuesday, November 1, 2011

What is the Secure Socket Layer(SSL)?

Read the article below from the Verisign web site and answer the questions below as comment posts.




How SSL  Works.

Encryption Protects Data During Transmission
Web servers and Web browsers rely on the Secure Sockets Layer (SSL) protocol to create a uniquely encrypted channel for private communications over the public Internet. Each SSL Certificate consists of a public key and a private key. The public key is used to encrypt information and the private key is used to decipher it. When a Web browser points to a secured domain, a level of encryption is established based on the type of SSL Certificate as well as the client Web browser, operating system and host server’s capabilities. That is why SSL Certificates feature a range of encryption levels such as "up to 256-bit".
Strong encryption, at 128 bits, can calculate 288 times as many combinations as 40-bit encryption. That's over a trillion times a trillion times stronger. At current computing speeds, a hacker with the time, tools, and motivation to attack using brute force would require a trillion years to break into a session protected by an SGC-enabled certificate. To enable strong encryption for the most site visitors, choose an SSL Certificate that enables at least 128-bit encryption for 99.9% of Web site visitors. True 128-bit SSL Certificates

Credentials Establish Identity Online
Credentials for establishing identity are common: a driver’s license, a passport, a company badge. SSL Certificates are credentials for the online world, uniquely issued to a specific domain and Web server and authenticated by the SSL Certificate provider. When a browser connects to a server, the server sends the identification information to the browser. To view a Web sites’ credentials and no that you are safe:
  • Click the closed padlock in a browser window
  • Click the trust mark (such as the VeriSign Trust™ Seal)
  • Look in the green address bar*
  • Insure that the Domain returned by the certificate contains "https"
*Only SSL Certificates with EV trigger high-security Web browsers to display your organization’s name in a green address bar. Learn more: SSL Security and Extended Validation

Authentication Generates Trust in Credentials
Trust of a credential depends on confidence in the credential issuer, because the issuer vouches for the credential’s authenticity. Certificate Authorities use a variety of authentication methods to verify information provided by organizations. VeriSign, the leading Certificate Authority, is well known and trusted by browser vendors because of our rigorous authentication methods and highly reliable infrastructure. Browsers extend that trust to SSL Certificates issued by VeriSign.
1. What  do you think encryption is?   Try to reason it out!!

2. Why is utilizing the SSL so critical for an ecommerce site??

3. As a shopper what are the two ways you can tell if a sight uses SSL?