auto apply to deposit invoice

[keke]

Hi, All
Is it possible for auto apply to be done on deposit invoice in the receivables module. that is , is it possible for sales invoice to automatically be applied to deposit invoice without clicking on the apply button in the sales invoice screen. my client do not want to go into the system and click apply deposit to sale invoice , he want the system to do the application for him without clicking the apply deposit.
please, kindly treat as urgent because my client is on my neck
regards,
keke