for example i will enter some value and i will press F11.it should be display that record

• there are two blocks in your form
  
• the first block (you call it a "header" one - I prefer "master") is a control block, which means that it is not based on a table
  
• the second block (you call it a "line level" block - I prefer "detail") is a database block - at least, that's what you said: Quote:

  line level block is created on data base table

  
  
• this is how it works: you enter some values into master block items. Then you push the "FIND" button. The result should be displayed in the detail block, i.e. display all records from a table that satisfy condition entered into the master block.
  
• it means that you have a few options to do that:
  • one is to - in WHEN-BUTTON-PRESSED trigger - use SET_BLOCK_PROPERTY and set detail block's ONETIME_WHERE property so that it looks like a WHERE clause in SELECT statement. It would ensure that only desired records are fetched
    
  • or, in PRE-QUERY detail block trigger, set search criteria as

    :detail.id := :master.id;
    :detail.name := :master.name;

    etc.
  
  WHEN-BUTTON-PRESSED on the "FIND" button should - somewhere at the end of the code - contain

  GO_BLOCK('detail');
  EXECUTE_QUERY;