Only assignment, call,increment and new object expressions c

Question

string isEditable=grdDesignation.DataKeys[index].Values["IsDeletable"].ToString();

if (isEditable == "True")

            {

                chkEditable.Checked = true;

            }

            else

            {

                chkEditable.Checked = false;

            }

I just shortned the code to below like this but showing the errors 

Only assignment, call,increment and new object expressions c

(isEditable == "True") ? chkEditable.Checked=true : chkEditable.Checked = false;