
This is a how-to on managing links within InDesign.
You can view the document link(s) status throught the Links Pallette:

If a yellow triangle appears next to a file name in the Links palette, the link is outdated. You must update the link in order for InDesign to display and print the most recent version of the linked file. If a question mark appears beside a file name in the Links palette, the link is broken. You must relink to the file in order for it to print at full resolution and for update notification to work.

When you open a document that has modified or missing links, an alert warns you of the problem. In the alert dialog box, you can click Fix Links to begin updating and relinking items immediately, or you can click OK to open the document and use the Links palette to update and relink items.
To update links:

Select the links you want to update; if you want to update all links, do not select any of them in the Links palette. Otherwise, select only the links you want to update. Hold down Shift (Mac OS) or Ctrl (Windows) to select multiple links.
Choose Update Link from the Links palette menu.
Note: You cannot update broken links.
Fix broken links:

To fix a broken link, you must relink to the text or graphic file.
To relink files:

If you want to relink all missing files, do not select any links in the Links palette. Otherwise, select the file or files you want to relink.
Choose Relink from the Links palette menu.
Browse to the original file (or its replacement) in the Relink dialog box.
Click Open or OK.