Oracle Forms

Dear all,
I have a situation where i have to check duplicate data entry(on a particular field,which is a mandatory field,i.e. it cannot be skipped by user without entering value) while data key-in in a Multi Record block.

As for reference I have used a logic,such as
1>In a When-Validate-Record trigger of that block I am assigning the value of that current item in Table type variable(collection type)
as this trigger fire every time as soon as i leave that record,so its assigning the value of that current time.And this process continues

then
2>In a When-Validate-Item trigger of that corresponding item(i.e. the trigger is at item level) has been written,where it compares the value of that current item and the value stored in Table type variable(collection type) of When-Validate-Record trigger.If the current item value is matched with any value stored in Table type variable I am showing a message of ('Duplicate Record') following by raise_form_trigger failure


This code is working fine for checking duplicate value of that multi record field

The problem is that,if user enter the value in that field,and then goes to next field,enter value to that field and then press 'Enter Query 'icon,the bolth Validate trigger fires.As result first when-validate record fires,which stores that value,and then when-validate-item fires,as a result it shows duplicate record message


Please give me a meaningful logic or code for solving this problem



Any other logic to solve this problem is also welcome