代码如下：
{eyou:searchform type='default'}
<form method="get" action="{$field.action}" onsubmit="return searchForm();">
{$field.hidden}
<input type="text" name="keywords" id="keywords" placeholder="请输入关键字">
<input type="submit" value="搜索">
</form>
<script>
function searchForm()
{
var keywords = document.getElementById('keywords').value;
if (keywords == '') {
alert('请输入关键字');
return false;
}
return true;
}
</script>
{/eyou:searchform}