Você não precisa mudar nada no código da caixa de pesquisa .Para adicionar esse widget na barra lateral do Blogger , sem fazer qualquer modificação , a largura da barra lateral deve ter pelo menos 305 px de largura. Você pode adicionar este gadget de pesquisa em seu blog seu blog Blogger em poucos minutos, é muito fácil de configurar. Vejamos como:
Faça login, clique em "Design" depois em "Editar HTML"
Copie o código abaixo e cole ANTES da tag </head>
<style type="text/css">
.subbox{width:305px;border:0 solid #141414;overflow:hidden}
.addthis_toolbox{padding:15px 0 5px 0;text-align:center}
.addthis_toolbox .custom_images a{width:32px;height:32px;margin:0 4px 0 4px;padding:0}
.addthis_toolbox .custom_images a:hover img{opacity:1}
.addthis_toolbox .custom_images a img{opacity:0.85}
.rssbox{background:#f7f6f6;border:1px solid #ccd1d7;padding:5px 10px;margin:10px 0 0 0;-moz-border-radius:10px;-khtml-border-radius:10px;-webkit-border-radius:10px;border-radius:10px;width:125px}
.rssbox:hover{border:1px solid #92aed1}
.rssbox a{color:#7c8a9b;text-transform:uppercase;text-decoration:none;font:bold 12px Arial,Helvetica,Sans-serif}
.rssbox a:hover{color:#7c8a9b;text-decoration:underline}
.emailsbox{background:#f7f6f6;border:1px solid #ccd1d7;padding:5px 10px;margin:10px 0 0 0;-moz-border-radius:10px;-khtml-border-radius:10px;-webkit-border-radius:10px;border-radius:10px;width:125px}
.emailsbox:hover{border:1px solid #92aed1}
.emailsbox a{color:#7c8a9b;text-transform:uppercase;text-decoration:none;font:bold 12px Arial,Helvetica,Sans-serif}
.emailsbox a:hover{color:#7c8a9b;text-decoration:underline}
.twitterbox{background:#f7f6f6;border:1px solid #ccd1d7;padding:5px 10px;margin:10px 0 0 0;-moz-border-radius:10px;-khtml-border-radius:10px;-webkit-border-radius:10px;border-radius:10px;width:125px}
.twitterbox:hover{border:1px solid #92aed1}
.twitterbox a{color:#7c8a9b;text-transform:uppercase;text-decoration:none;font:bold 12px Arial,Helvetica,Sans-serif}
.twitterbox a:hover{color:#7c8a9b;text-decoration:underline}
.facebookbox{background:#f7f6f6;border:1px solid #ccd1d7;padding:5px 10px;margin:10px 0 0 0;-moz-border-radius:10px;-khtml-border-radius:10px;-webkit-border-radius:10px;border-radius:10px;width:125px}
.facebookbox:hover{border:1px solid #92aed1}
.facebookbox a{color:#7c8a9b;text-transform:uppercase;text-decoration:none;font:bold 12px Arial,Helvetica,Sans-serif}
.facebookbox a:hover{color:#7c8a9b;text-decoration:underline}
#search{width:290px;padding:2px 2px;background:#f7f6f6;border:1px solid #ccd1d7;height:28px;margin-top:0;margin-left:5px;display:inline;float:left}
#search:hover{border:1px solid #92aed1}
#search form{margin:0;padding:0}
#search fieldset{margin:0;padding:0;border:none}
#search p{margin:0;font-size:85%}
#s{width:200px;margin:0 0 0 0;padding:5px 5px 5px 5px;border:none;font:normal 80% "Tahoma",Arial,Helvetica,sans-serif;color:#000;float:left;background:#f7f6f6;display:inline}
input#searchsubmit{float:right;display:inline;margin:0 0 0 0;height:28px;background:#b2b2b2;color:#000;border:0 solid #222}
</style>
Salve o template e volte a sua página Design, clique em adicionar um gadget, escolha a opção "HTML/Javascript ", copie o código abaixo e cole dentro do box do gadget. Salve e pronto.
<div class="subbox">
<div id='search' style='display:inline;'>
<form action='/search' id='searchform' method='get'>
<input id="s" name="q" onblur="if (this.value == "") {this.value = "Search...";}" onfocus="if (this.value == "Search...") {this.value = "";}" type="text" value="Search..." />
<input id="searchsubmit" type="submit" value="Search" />
</form>
</div>
<table><tr>
<td><div class="rssbox">
<a href="http://feeds.feedburner.com/FEEDBURNER-ID" target="_blank" rel="nofollow"><img src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhV-PO2cHf_tVVpb4icNaoEUaH78ap_49-ItS6S94wTxG0uA8Lro6a53ibN1jFL4Yp-5iFzbu0IdrjYMUMwa12qElLuTEjlMmLlbnIz5yCx3k8h3cNhf7kiQweQYJ1xtl-o23-_dpC1XgLA//" alt="RSS Feed" title="RSS Feed" style="vertical-align:middle; margin-right: 5px;border:none;" /></a><a href="http://feeds.feedburner.com/FEEDBURNER-ID" target="_blank" rel="nofollow">RSS Feed</a>
</div></td>
<td><div class="emailsbox">
<a href="http://feedburner.google.com/fb/a/mailverify?uri=FEEDBURNER-ID" target="_blank" rel="nofollow"><img src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiseGAoCw-bv_3L4TJAtNpzRxRmh4jwcsLtzgyaPsb1VrcccL-tdiNvRUJ4BUu_YrgFQqQO9TTce011hECCDgDJ7GeAjdYjYpRoq6E7jErE8Gn6TnMDMuXvWsL_UidgPlKG4HMTYty-wjdM//" alt="EMail Feed" title="EMail Feed" style="vertical-align:middle; margin-right: 5px;border:none;" /></a><a href="http://feedburner.google.com/fb/a/mailverify?uri=FEEDBURNER-ID" target="_blank" rel="nofollow">EMail Feed</a>
</div></td>
</tr><tr>
<td><div class="twitterbox">
<a href="http://twitter.com/TWITTER-USERNAME" target="_blank" rel="nofollow"><img src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiS4cNdKLjzJvGt4KKWlzzq11o2vcV4af635DoefRVmR1MfPNexog5u556HGaL1a5SMxP9B3i16lrZTa6Nd1x_qxZNvn8nriW26W5gxrzkRkCqnq57tJ5x0AwcbA6wqBvPKSTHVbYj5Oc-y//" alt="Twitter" title="Twitter" style="vertical-align:middle; margin-right: 5px;border:none;" /></a><a href="http://twitter.com/TWITTER-USERNAME" target="_blank" rel="nofollow">Twitter</a>
</div></td>
<td><div class="facebookbox">
<a href="http://www.facebook.com/FACEBOOK-USERNAME" target="_blank" rel="nofollow"><img src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg8DQu4t227KXjNAj4MI35RpS_KKNnaH7a4ibo3S-kOCrPERyXzr22Yaz-lRcN_i8dCqMM7WULdrwIEDlOMFt2-lN5L3Gia5WTi6B0OBk5UUtmCKL4Rj02iaAawiusqE2yVEhj6kQp5Eng5//" alt="Facebook" title="Facebook" style="vertical-align:middle; margin-right: 5px;border:none;" /></a><a href="http://www.facebook.com/FACEBOOK-USERNAME" target="_blank" rel="nofollow">Facebook</a>
</div></td>
</tr></table>
<p style="display:none;" align="center">Widget by <a href="http://www.bloggertipandtrick.net/" target="_blank">Blogger Tips And Tricks</a></p>
<div class='addthis_toolbox'>
<div class='custom_images'>
<a class='addthis_button_twitter'><img alt='Twitter' height='32' src='https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgluz6ctxsBNskLauMaNqusdw5hBdjCcPntWRrY_-uY4a8XzJHZ2yDAtPl4UrKziH3HDjcjuDLFvGB-8suEkVtDDDv6wOQDLekLLssReU8Pr3vX83C2uVH4o6viwv-evayzCb76Q7pYy4g//' width='32'/></a>
<a class='addthis_button_delicious'><img alt='Delicious' height='32' src='https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiBPglpa0Qa75799JeSMd_ot9ElEB9CN8PUYF8FzLMzoKS1QHm62v1VFUA23jDccmNi0ajTlBGxoh2c4u26ThU6zTDoayxDwg67LEIga9EbJEzT-PixaBDjVBzrdASjsulVQQjaMAE_vgg//' width='32'/></a>
<a class='addthis_button_facebook'><img alt='Facebook' height='32' src='https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgyzNl0ds_nnxUwfam3R32F0_WaoSwzh_g0GqCRhqFfLlnnmJaouL44uHbpKMYArVywakKfpxyb7AHF84n0CjctJWJtvy2y2VrRWOi6GlfomGOeObaIpMF7mTbGiOR-eSox6cQ5hr4us5o//' width='32'/></a>
<a class='addthis_button_digg'><img alt='Digg' height='32' src='https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiBa5KV40nb241sAxCpXUxA258r-y14b741WiUj86DrgC3QuInNB6Deh9ZQHmNiYGqIFt8PkzWyWoLT7s83RqK7R8w5nmrF_POXvKUX4hkC-5Xqt4ulQjMMwGl193Fv1Xh0jVMO4-Xy9Yw//' width='32'/></a>
<a class='addthis_button_stumbleupon'><img alt='Stumbleupon' height='32' src='https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhjJk5H3VL7Gc-SoxLykX6v4i4LtyOt_PnnqL1daFn_8GiluJymhJ7TO6w22i2tSqgodat5xhyphenhyphennucMW0x6R1Pnp2Y75HKdbcyVdaIOts6Y-opJLlDEGqntfHWMqe16CQ1l3uc_Q651V_eg//' width='32'/></a>
<a class='addthis_button_favorites'><img alt='Favorites' height='32' src='https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgQwF1uzs6emfpdHdA6wMFxlb4jOEIA3h_7dztXCRSOAiDhSPbSF_zAxebyDUPw4zeI7js-mcS8vhTOnqAQdyb6L3QmEUzFGydzfFBbXovtTX5r0o5qQ_HerDgv8ZD0beW5LjpYImq3bPQ//' width='32'/></a>
<a class='addthis_button_more'><img alt='More' height='32' src='https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh-VB54vz4PNmz1X5PxOJd_GrBpbMPQYFnQBl5MIGW2J-KtnXnuiTGAHGNFhfHjqg7_Ax5hk4z6SL0Il0uBbMKPTb3yO4fITlspFiqkxcoL3ahTT_N5fPdq_AjsKfFRyRiArSwezF5Z8is//' width='32'/></a>
</div>
<script src='http://s7.addthis.com/js/250/addthis_widget.js' type='text/javascript'/>
</div>
</div>
Configure as partes grifadas:
FEEDBURNER-ID ► Seu Feedburner ID.(4 vezes).
TWITTER-USERNAME ►Seu Twitter username.
FACEBOOK-USERNAME ►Seu Facebook username.
Caso você tenha algum conhecimento de html e CSS, poderá fazer algumas mudançs para adequar melhor ao seu layout.
É isso. Beijo da Mama♥