Actually, we have 2 shape box of Google search. let you choice that appropriate with yours.
To add Google search engine to your blog, follows the step below.
1. Go to Template of blogger
2. Click Layout - Click Page Elements - Click Add a Page Element - Click HTML/JavaScript (Paste The Code below) - Click save
3. Ok, Finish
The code is :
<form method="get" action="http://www.google.com/search">
<div style="border:1px solid black;padding:4px;width:20em;">
<table border="0" cellpadding="0">
<tr><td>
<input type="text" name="q" size="25"
maxlength="255" value="" />
<input type="submit" value="Google Search" /></td></tr>
<tr><td align="center" style="font-size:75%">
<input type="checkbox" name="sitesearch"
value="wahyoku.blogspot.com" checked /> only search Wahyoku Blog<br />
</td></tr></table>
</div>
</form>
Here's how that renders when included on an HTML page:
Biside above shape, you also can choice the other shape (There are two null button entire on the search box : Your name`s blog and entire World Wide Web).
The second code is :
<form method="get" action="http://www.google.com/search">
<input type="text" name="q" size="31"
maxlength="255" value="" />
<input type="submit" value="Google Search" />
<input type="radio" name="sitesearch" value="" />
The Web
<input type="radio" name="sitesearch"
value="askdavetaylor.com" checked /> Ask Dave Taylor<br />
</form>
Note :
1. Change "Wahyoku.blogspot.com" with your blog.
2. "255" is the max amount of caracter in box (you can changed it)
The other tips to learn about adding search box on the blog, pls Read here.