onSubmit="checkAndConfirm()"
function checkAndConfirm(){
// check 和 confirm同颂雀脊时野渗为true时 提交
return check()&&confirm( '是否提岁纤交？ ');
}
<html>
<script>
function check(){
alert();
}
</script>
差蠢<body>
<form action='http://www.baidu.com'虚神陪 onSubmit='check();return confirm( "是瞎弯否提交？")'>
<input type='submit'>
</form>
</body>
</html>