public/ckeditor/4.4dev/core/dom/element.js
function() {
			// CSS unselectable.
			this.setStyles( CKEDITOR.tools.cssVendorPrefix( 'user-select', 'none' ) );

			// For IE/Opera which doesn't support for the above CSS style,
			// the unselectable="on" attribute only specifies the selection
			// process cannot start in the element itself, and it doesn't inherit.
			if ( CKEDITOR.env.ie ) {
				this.setAttribute( 'unselectable', 'on' );

				var element,
					elements = this.getElementsByTag( '*' );

				for ( var i = 0, count = elements.count() ; i < count ; i++ ) {
					element = elements.getItem( i );
					element.setAttribute( 'unselectable', 'on' );
				}
			}
		}
function() {
			// CSS unselectable.
			this.setStyles( CKEDITOR.tools.cssVendorPrefix( 'user-select', 'none' ) );

			// For IE/Opera which doesn't support for the above CSS style,
			// the unselectable="on" attribute only specifies the selection
			// process cannot start in the element itself, and it doesn't inherit.
			if ( CKEDITOR.env.ie ) {
				this.setAttribute( 'unselectable', 'on' );

				var element,
					elements = this.getElementsByTag( '*' );

				for ( var i = 0, count = elements.count() ; i < count ; i++ ) {
					element = elements.getItem( i );
					element.setAttribute( 'unselectable', 'on' );
				}
			}
		}
function ( ) { // CSS unselectable. this . setStyles ( CKEDITOR . tools . cssVendorPrefix ( 'user-select' , 'none' ) ) ; // For IE/Opera which doesn't support for the above CSS style, // the unselectable="on" attribute only specifies the selection // process cannot start in the element itself, and it doesn't inherit. if ( CKEDITOR . env . ie ) { this . setAttribute ( 'unselectable' , 'on' ) ; var element , elements = this . getElementsByTag ( '*' ) ; for ( var i = 0 , count = elements . count ( ) ; i < count ; i ++ ) { element = elements . getItem ( i ) ; element . setAttribute ( 'unselectable' , 'on' ) ; } } }
Makes the element and its children unselectable.

var element = CKEDITOR.document.getById( 'myElement' );
element.unselectable();

@method
Makes the element and its children unselectable .