Please help! Lookup fields

Please help! Lookup fields

We have a main database that we input all details into.  We have another database where we used a script with a Lookup field to pull details across.
 
I want to create another database that uses the same script and Lookup field to pull details across from the main database but it wont work.
 
Can more than one Lookup script be used on the same database??
 
Thank you in advance for a speedy response.