How to import metadatas from a database

[mahdi]

hi,
I'm working on an extension that include these steps:
1- create a new content type (which is in fact, a table (named project) in my database) with new metadatas (the fileds of the table)
2- import a new document
3- assign the type content to the doc
4- import the values of metadata from the database automaticlly.( the import is related to the number of project (numproj) which is the primary key of the table project)

now, i'm trapped in the step 4

in fact i want to, when i tape the value of numproj, the rest of metadata will automaticlly imported from the table)

i tried to update the add-content-Dialog.jsp but i didn't find how to manipulate the metadatas

so please help;

[mahdi]

i'm trying now to modify the jsp pages "…\content\add-content-dialog.jsp" and "…\content\edit-content-properties.jsp"
i'm thinking in  creating a bean, in which i defined the properties of my model manually and i defined the methods which manipulate the values (to be imported from the Data Base) of these properties.   
so is it possible ?, if yes could you please show me how to create and deploy a customised bean in alfresco.
thanks.

[mahdi]

can somebody help???