原生的javascript 提交表单问题

Question

HTML页面上有个ID='loginform'的form表单,为什么我在chrome的右键控制台上写
document.getElementById('loginform').submit();
结果报错了

Uncaught TypeError: document.forms.loginform.submit is not a function
    at <anonymous>:2:29
    at Object.InjectedScript._evaluateOn (<anonymous>:905:140)
    at Object.InjectedScript._evaluateAndWrap (<anonymous>:838:34)
    at Object.InjectedScript.evaluate (<anonymous>:694:21)