the client needs us to lock ( read only) value on applied amount under receipt line item application

Summary:

• under receivables--> receipt creation -->the client needs us to lock ( read only) value on applied amount under receipt line item after applying invoice and saving it.
  -the correct approach was to use sandbox--> page editor --> select applied amount box and use an expression based on application status of receipt.

-the correct expression is :
#{row.bindings.Status1.inputValue =='Applied'}
this checks the application status input value if Applied then the applied amount field will be locked(read only). i it should work however the expression editor is returning false when it should return true on applied receipts. the problem lies with the string it is comparing to however there is no lower case letter errors. it is an exact match. and the binding name Status1 is the correct binding name for the application status input field.