posting amount cash money in field of credit amount in cash recipt journal it posting in customer ledger entry table in debit amount field why

I have problem when i want to make payment in cash receipt journal from specified customer and writing in credit amount field is 2000 after posting

it register in customer ledger entry table as 2000 in debit amount field why .

the correct it must register in credit amount field.

my steps (i select account type customer document type payment then select customer specified then make post)

what is the reason of this problem and how i solve this.

thanks