如何在百度站内搜索前对数据或都其它内容进行处理？

<script language='javascript'>
function g(formname){
var url = "http://www.baidu.com/baidu";
if (formname.s[1].checked) {
formname.ct.value = "2097152";
}
else {
formname.ct.value = "0";
}
formname.action = url;
return true;
}
//在百度搜索前进行处理
function b(before){
//这里自定义处理操作
//alert('this is done!');
g(before);
}
</script>
<form name="f1" onsubmit="return b(this)" target="_blank">
<ul>
<li>
<input name='word' size='30' maxlength='100' class='se_form_cl' style="font:14px/1.5 Tahoma,'Microsoft Yahei','Simsun';color:#999;" autocomplete="off" x-webkit-speech speech />
<input name='tn' type='hidden' value='bds' />
<input name='cl' type='hidden' value='3' />
<input name='ct' type='hidden' />
<input name='si' type='hidden' value='www.my2400.com' />
<input name='ie' type='hidden' value='utf-8' />
<span style="display:none;">
<input name='s' type='radio' />
互联网
<input name='s' type='radio' checked='checked' />
www.baidu.com</span> </li>
<li class="se_form_but" title="搜索">
<input type="submit" value="search" style="width:97px;height:35px;cursor:pointer;opacity:0;filter:alpha(opacity=0)" />
</li>
</ul>
</form>