Inserts the specified contents at the caret position.
function(h, skip_undo) {
			var ed = this.editor, r = ed.selection.getRng();

			// First delete the contents seems to work better on WebKit when the selection spans multiple list items or multiple table cells.
			if (!ed.selection.isCollapsed() && r.startContainer != r.endContainer)
				ed.getDoc().execCommand('Delete', false, null);

			ed.execCommand('mceInsertContent', false, h, {skip_undo : skip_undo});
		}