In pages the table of contents in left side bar is not showing all the headings

Hi Friends

I have been using pages extensively for sometime now. Most of the times I navigate through the document by using the table of contents on the side bar. I have selected only the Heading 1 to display in table of contents. But in one document I am able to see only first two headings and after that the headings are not displayed in table of contents. I have tried to change the Heading 1 to body and then back to Heading 1 with a hope that it will be updated but it is not helping. I have also tried to re open the document but no improvement. Thanks in advance if you have read it or have any solution.