jquery - Froala Editor how save content to textarea before send form -

i use in project froala. textarea element in form sent server. add text froala , click submit form button. textarea field on server empty(null). think need call froala method prepare textarea before submitting form server, not know one.

what problem?

view

@using (html.beginform("updatepost", "post", formmethod.post, new { id = "postform" })) {     <textarea id="previewtext" name="previewtext"></textarea>     <button class="btn btn-success w-100">save</button> } 

server

[httppost] public jobject updatepost([fromform] post postform) {     //... } 

javascript

       $('#previewtext').froalaeditor({             language: 'ru',             imageuploadurl: '../uploadimage',             imageuploadparams: {                 postid: tmigin.cms.posteditor.postid             },             imagemanagerloadurl: '../loadimages',             imagemanagerloadparams: {                 postid: tmigin.cms.posteditor.postid             },             imagemanagerdeleteurl: '../deleteimage',             imagemanagerdeleteparams: {                 postid: tmigin.cms.posteditor.postid             }         }); 

update similar problems in compatibility of jquery form plugin , froala.