Finish StudentLoginModal implementation

app/templates/courses/student-log-in-modal.jade

@@ -22,8 +22,10 @@ block modal-body-content
       .input-border
         input#password.input-large.form-control(name="password", type="password", value=view.formValues.password)
         
+    #errors-alert.alert.alert-danger.hide
+
     .text-center
-    button#log-in-btn.btn.btn-default(data-i18n="login.log_in")
+      input#log-in-btn.btn.btn-default(data-i18n="login.log_in", type="submit")
       p
         a#create-new-account-link(data-i18n="login.signup_switch")
   

app/views/courses/StudentLogInModal.coffee

@@ -13,11 +13,23 @@ module.exports = class StudentSignInModal extends ModalView
 
   events:
     'click #log-in-btn': 'onClickLogInButton'
+    'submit form': 'onSubmitForm'
+
+  onSubmitForm: (e) ->
+    e.preventDefault()
+    @login()
     
   onClickLogInButton: ->
-    forms.clearFormAlerts(@$el)
+    @login()
+
+  login: ->
     userObject = forms.formToObject @$el
     res = tv4.validateMultiple userObject, User.schema
     return forms.applyErrorsToForm(@$el, res.errors) unless res.valid
-    @enableModalInProgress(@$el) # TODO: part of forms
-    loginUser userObject, null, window.nextURL
+    @enableModalInProgress(@$el)
+    auth.loginUser userObject, (jqxhr) =>
+      error = jqxhr.responseJSON[0]
+      message = error.property + ' ' + error.message
+      @disableModalInProgress(@$el)
+      @$('#errors-alert').text(message).removeClass('hide')
+