title: Adding extra information in sales_flat_quote and sales_flat_order_item tables
body: <p>I am just getting to grips with magento and i am trying to work out how to do the following. </p>
  
  <p>This is what i have currently </p>
  
  <ol>
  <li>When a customer loads the onepage.phtml file an include is made to a script that checks the items in the basket and calls an api which generates a unique order url for the customer. </li>
  </ol>
  
  <p>This is what i need to do </p>
  
  <ol>
  <li>I then need to store this unique order url in the database sales_flat_order table. The reason i need to do this is i have an observer i have created which once the order is paid . A second api call is made which passes this unique_order_url back to finalise the order and complete payment.</li>
  </ol>
  
  <p>So to summarise i need to pass this unique_order_url that is generated as part of onepage.phtml so that it is included in the database once an order is placed. </p>
  
  <p>I have created the coloumn in sales_flat_order as a varchar but i am struggling on where to go from here </p>
  
  <p>Any help / advice would be much appreciated </p>