dual test on submit

[shrive22]

I have a clients table and a documents table, each client has many documents.  I have a page that lets the user either input a text field the client number or select the client from a select list.  Wehn the form is submitted I want it to :

if((text && select have values) && (values agrees){
select clients documents from db
} elseif(text has value) {
select clients documents from db
} else {
select clients documents from db from select list
}

 

I am having a hard time coming up with a way to do this.  Should I have two forms one for the text input and one for the select and then test to see if both have been submitted?

 

any ideas are appreciated

 

thanks