I will be making it very easy to create a custom redirect page (Error 404 page). This page is very important in a blog/website because everybody needs guidiance. If I open an error page with no links redirecting to another page, the next thing I will do is leave the page, and I know you would do thesame.
Now, let's begin the journey!!!

I will be using a CSS code which really make things simple and would add slight modifications to make the error box more attractive.
Our 404 page will prompt visitor that
he has landed a wrong page and will
provide him three important options
which are: Go Back to the page from where
he came from. (We will use
JavaScript here). Contact the Admin and inform
him about the broken link. (This
will help you track broken links). And finally to provide a link to
homepage. So lets get to work to achieve all the
above. Simply follow the easy steps
below to display 404 error message
uniquely. 1. Go To draft.blogger.com > Settings >
Search Preferences 2. Click on Edit link next to : Custom Page Not Found 3. Inside the box paste the following
code: <!-- MBT Default Template -->
<div class='MBT-404-box'>
<p style='line-height:
30px'><strong>
<font color='#ff0000' size='5'> Oops! </font> <font color='#666666'> Looks like you either clicked a broken link or a Page that no more exits. Kindly do one of the followings: </font></strong></p>
<ol style='line-height: 25px'>
<li><a href='javascript:history.go
(-1)'>&#171; Go Back</a> </li> <li>Report the Problem to us by <a href='http:// contact.dezzytech.com'> Clicking Here</ a>&#160;&#160;&#160;
(<em>This will help us serve you even better</em> </li> <li>Go To Homepage by <a href='http:// www.dezzytech.com'> Clicking Here</a> <br/></li> </ol>
<p> <br/>
<br/>
<br/></p> <p align='center'><font color='#0080ff' style='font-size:
150px'><strong>404</strong></ font></p>
<p>&#160;</p>
<p align='center'/>
<p align='center'><font
size='5'>Page Not Found!</font></ p>
</div> Make these customizations: You can edit the bolded texts
with anything you like Replace http:// contact.dezzytech.com
with link of your contact page Replace http:// www.dezzytech.com with
your homepage link 4. Click the Save changes button and you are half way done. 5. Now go to Template > Edit HTML 6. Search for this ]]></b:skin> 7. Just below it paste the following code stylsheet code: <b:if cond='data:blog.pageType ==
&quot;error_page&quot;'>
<style type='text/css'>
.status-msg-wrap {
font-size: 100%;
margin: none; position: static;
width: 100%;
}
.status-msg-border {
display:none
} .status-msg-body {
padding: none;
position: static;
text-align: inherit;
width: 100%;
z-index: auto; }
.status-msg-wrap a {
padding: none;
text-decoration: inherit;
}
.MBT-404-box { background:#FFFFFF; width:98%;
margin:10px 0px;
padding:20px 10px;
border:1px solid #ddd;
-moz-border-radius:6px;
-webkit-border-radius:6px; border-radius:6px;
box-shadow: 5px 5px 5px #CCCCCC;
}
</style>
</b:if> To change the background colour of the box edit #FFFFFF 8. Save your template
9. Done! Visit any page of your blog that do not exist and check if it is working. Example: www.dezzytech.com/ajppgmjmg

Ar u talking about blogger alone or every website? Basically, 404 error page is not a big deal. Just use html and css to design a web page that has links to: homepage, contact us page and sitemap page. Then save it in ur root folder as 404.html or 404.php. When a user enters a wrong webpage or broken link, ur host will automatically detect the 404 page in ur root folder and display it by default. No javascript is needed. Most web host now detect 404.php in ur folder and displays it when things go wrong.

^^ guy, u just killed it.

*solid*:
^^ guy, u just killed it.

Try it and see. If it didnt work, tell ur host company to just configure it.