html:
<form id="frmUserLogin" action="/index.php/admin/login/check" method="post" target="_top">
<input type="hidden" name="referer" value="" />
<label>帐号:</label><input id="username" name="username" type="text" class="textbox_middle" value="" /><br>
<label>密码:</label><input id="password" name="password" type="password" class="textbox_middle" /><br>
<input id="btnSubmit" type="button" value=" 登录 " class="button" /><br>
</form>
js:
$("#frmUserLogin").find("#btnSubmit").click(function(event){
var username = $("#frmUserLogin").find("#username").val();
var password = $("#frmUserLogin").find("#password").val();
console.log(username);
$("frmUserLogin").submit();
});