plpgsql function question

Hi,
 
   I am having a requirement here.
 
   1) I need to write a plpgsql function where it takes the input parameter of a structure of a table.
   2) The table has 15 columns
   3) It does lots of validation based on the parameter and finally returns an integer as output parameters
 
  Q) How will I passe the table structure as as parameter
      2) Do I need to create a type?
 
   Please help me.
 
Regards
skarthi