Set CKeditor First letter Cap's Using Jquey KeyUp

Question

In my application i am using Ckeditor, by default ckeditor first letter is not capital, So i need to convert first letter to upper case, that is automatically change lower to upper, for that i am using jquery Keyup event, and i tried with below code:

 $(document).ready(function () 
{ 
  CKEDITOR.on('instanceCreated', function (e) {
     e.editor.on('contentDom', function () {  
      e.editor.document.on('keyup', function (event) {
 if (this.selectionStart == 0 && event.data.$.keyCode >= 65 && event.data.$.keyCode <= 90 && !(event.data.$.shiftKey) && !(event.data.$.ctrlKey) && !(event.data.$.metaKey) && !(event.data.$.altKey)) 
{ 
var $t = $(this);
 event.data.$.preventDefault();
 var char = String.fromCharCode(event.data.$.keyCode);
 $t.val(char + $t.val().slice(this.selectionEnd));
 this.setSelectionRange(1,1); 
} 
});
 });

 

and aspx code is:

 <CKEditor:CKEditorControl ID="CKEditor1" BasePath="~/ckeditor/" runat="server" Width="940px" Height="400px"></CKEditor:CKEditorControl> 

here, this.selectionStart is undefined, here how can i call the this.selectionStart ?

TIA