<!--HTML-->
<form id='test_form' action='' method='' omsubmit='return checkForm()'>
<input type='text' name='username' value=''/>
<input type='password' name='pwd' value =''/>
<button type='submit'>提交<button/>
<form/>
<script>
function checkForm(){
var form = document.getElementById('test_form');
//可在此修改input
//进行下一步
form.submit();
}
</script>
