MySQL DB Column Not Updating after TinyMCE post INSERT
===

I've managed to implement a simple TinyMCE editor on my site and have it call using mySQL database. My problem Im having now is getting the DB to overwrite the contents already stored inside with what is being posted?

I simply want to overwrite the table contents (within the column) with what is being inserted. 
 
     Here is my code:

    <!--- CONNECT TO THE DATABASE------>
     <?php
     $con = mysql_connect("localhost","root","jdkldk8%by");
     if (!$con)
      {
       die('Could not connect: ' . mysql_error());
       }

     mysql_select_db("cms", $con);

     $sql="INSERT INTO tinymce (contents, contact, slider, resources)
     VALUES
     ('$_POST[contents]','$_POST[contact]','$_POST[slider]','$_POST[resources]')";

     if (!mysql_query($sql,$con))
     {
     die('Error: ' . mysql_error());
       }
     echo "1 record added";
     mysql_close($con);
     ?>

     <!--- END DATABASE SETTINGS ----->


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