There is a list called “Customer Equipment” and its form was customized by InfoPath 2010. One of the field is called “Customer” which is a look-up field (a dropdown list).
When add a new item I want to pass the customer ID from the URL query string like this:
and the customer with that ID in the “Customer” dropdown list will be automatically selected.
Step by step:
More Details: http://www.sharepointlearning.net.au/sharepoint_article_details.aspx?articleID=17&title=Pass%20query%20string%20to%20a%20SharePoint%20list%E2%80%99s%20%E2%80%9CAdd%20new%20item%E2%80%9D%20form%20that%20was%20customized%20by%20InfoPath%202010